Dielectric ceramic composition and monolithic ceramic capacitor using same

ABSTRACT

The present invention provides a dielectric ceramic composition containing 100 parts by weight of essential component represented by (BaO) m  TiO 2  +M 2  O 3  +R 2  O 3  +BaZrO 3  +MgO+MnO (wherein M 2  O 3  represents Sc 2  O 3  and/or at least one of Eu 2  O 3 , Gd 2  O 3 , Tb 2  O 3  and Dy 2  O 3 ) and 0.2 to 3.0 parts by weight of a side component represented by Li 2  O--(Si, Ti)O 2  --MO (wherein MO represents Al 2  O 3  and or ZrO 2 ) or SiO 2  --TiO 2  --XO (wherein XO represents at least one of BaO, CaO, SrO, MgO, ZnO and MnO), and a ceramic capacitor using the same.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dielectric ceramic composition and monolithic ceramic capacitor using the same.

2. Description of the Related Art

The conventional ceramic capacitor is usually produced by the following process.

First, a sheet of a dielectric material coated on its surface with an electrode material to serve as an inner electrode is prepared. A material essentially composed of BaTiO₃ is used for the dielectric material. Then, the sheet of the dielectric material coated with this electrode material is laminated with heat-pressing to form a monolithic body followed by firing at 1250 to 1350° C. in an environment to obtain a ceramic monolithic body having inner electrodes. A monolithic ceramic capacitor is obtained by glazing outer electrodes electrically connected to the inner electrodes.

Noble metals such as platinum, gold, palladium or silver have been conventionally used for the material of the inner electrode of this monolithic. ceramic capacitor. However, these electrode materials are expensive although having excellent characteristics, rendering the production cost high. Therefore, a monolithic capacitor using base metals such as Ni as the inner electrode is currently proposed to reduce the production cost, and its application in the market being steadily increasing.

In the trend to make electronic appliances compact, high performance and low price, strongly required is a monolithic capacitor of even lower price, improved in insulation durability, insulating property and reliability, and having a large capacitance. Although it is advantageous to use an inexpensive monolithic ceramic capacitor in which nickel is used for the inner electrode for reducing the price of the electronic appliances, there is the problem that the insulation resistance, insulation durability and reliability extremely deteriorate when the electronic appliances are used under a high electric field strength because conventional dielectric ceramic materials are designed on the premise that they are used under a low electric field strength. In other words, there has been no monolithic ceramic capacitor capable of use under a high electric field strength when using nickel for the inner electrode.

For example, while the dielectric materials disclosed in Japanese Examined Patent Publication No. 57-42588 and Japanese Unexamined Patent Publication No. 61-101459 display a large dielectric constant, the grain size of the dielectric ceramic is large, thereby exhibiting deficiencies such that the insulation durability of the monolithic ceramic capacitor becomes low when it is used under a high electric field strength or the mean life span under the high temperature load test is short.

In the dielectric material disclosed in Japanese Examined Patent Publication No. 61-14611, there was a deficiency that the dielectric constant, or the electrostatic capacitance, becomes extremely lowered when the capacitor is used under a high electric field strength, although its dielectric constant obtained under a low electric field strength is as high as 2000 to 2800. There is also the deficiency that the insulation resistance is low.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a dielectric ceramic composition capable of forming, for example, dielectric ceramic layers of a monolithic ceramic capacitor, wherein the insulation resistance represented by the product with the electrostatic capacitance (the product CR) is as high as about 4900 to 5000 Ω•F or more at room temperature and about 200 Ω•F or more at 150° C., respectively, when the capacitor is used under a high electric field strength of, for example, as high as about 10 kV/mm, along with having a small voltage dependence of the insulation resistance, excellent stability of the electrostatic capacitance against DC vias voltage, being high in insulation durability while the temperature characteristics of the electrostatic capacitance satisfies both the B-level characteristic standard stipulated in the JIS Standard and X7R-level characteristic standard stipulated in the EIA standard and having excellent weather resistance performance as shown by a high temperature load test and high humidity load test. Another object of the present invention is to provide a monolithic ceramic capacitor whose inner electrode is constructed of Ni or Ni alloys along with using such dielectric ceramic composition as the dielectric ceramic layer.

In broad terns, provided is a monolithic ceramic capacitor employing a dielectric ceramic composition comprising barium titanate, barium zirconate, manganese oxide, and at least one of Sc₂ O₃. Y₂ O₃, Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O₃ and Yb₂ O₃, as a also Li₂ O--(Si, Ti)O₂ --MO or SiO₂ --TiO₂ --XO, and optionally MgO.

In a first preferred aspect, the present invention provides a dielectric ceramic composition comprising barium titanate containing about 0.02% by weight or less of alkali metal oxides, at least one of scandium oxide or yttrium oxide, at least one of compound europium oxide, gadolinium oxide, terbium oxide and dysprosium oxide, and barium zirconate and manganese oxide, and corresponding to the composition formula

    (BaO).sub.m TiO.sub.2 +αM.sub.2 O.sub.3 +βR.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

(wherein M₂ O₃ represents at least one of Sc₂ O₃ or Y₂ O₃ and R₂ O₃ represents at least one of Eu₂ O₃, Gd₂ O₃, Tb₂ O₃ and Dy₂ O₃, α, β, γand g represent mo range of 0.01≦α<0.04, 0.01≦β≦0.04, 0.01≦γ≦0.04, 0.01<g≦0.12 and α+β≦0.05 with 1.01<m≦1.03),

along with containing about 1 to 2 parts by weight of either a first or second side component relative to 100 parts by weight of the essential component defined by said formula, wherein the first side component is an oxide represented by Li₂ O--(Si, Ti)O₂ --MO (wherein MO is at least one of Al₂ O₃ or ZrO₂) and the second side component is an oxide represented by SiO₂ --TiO₂ --XO (wherein XO is at least one of BaO, CaO, SrO, MgO, ZnO and MnO).

In the dielectric ceramic composition described above, the essential component may further contain h moles of magnesium oxide, where

0.001<g≦0.12, 0.001<h≦0.12and g+h≦0.13

In the dielectric ceramic composition according to another aspect of the present invention, the essential component may be represented by the following composition formula

    (BaO).sub.m TiO.sub.2 +αM.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

(wherein M₂ O₃ represents at least one of either Sc₂ O₃ or Y₂ O₃, where α, γ and g representing mole ratio in the range of 0.001≦α≦0.06, 0.005≦γ<0.06 and 0.001<g<0.13 with 1.000<m≦1.035).

The essential component may further contain h moles of magnesium oxide, where 0.001<g≦0.12, 0.001<h≦0.12 and g+h≦0.13.

According to a different aspect of the present invention, the essential component may be represented by the following composition formula

    (BaO).sub.m TiO.sub.2 +αR.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

(wherein R₂ O₃ represents at least one of Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O₃ and Yb₂ O₃, where α, γ and g represent moles in the range of 0.001≦α≦0.06, 0.005≦γ≦0.06 and 0.001<g≦0.13 with 1.000<m≦1.025).

The essential component may further contain h moles of magnesium oxide, where 0.001≦γ≦0.06, 0.001<g≦0.12, 0.001<h≦0.12 and g+h≦0.13.

In the dielectric ceramic compositions described above, it is preferable that the first side component, when its composition is represented by xLi₂ O--y(SiN_(w),Ti_(1-w))O₂ --zMO (wherein x, y and z represent mol % and w is in the range of 0.30≦w≦1.00), falls within or on the boundary lines of the area surrounded by straight lines connecting the points indicated by A (x=20, y=80, z=0), B (x =10, y=80, z=10), C (x=10, y=70, z=20), D (x=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0) provided that when the composition falls on the straight line of A-F, w is within the area of 0.3≦w<1.0 on a three component diagram defined by the apexes corresponding to each component.

In the dielectric ceramic compositions described above, it is preferable that the second side component, when its composition is represented by xSiO2--yTiO₂ --zXO (wherein x, y and z represent mol %), falls within or on the boundary lines of the area surrounded by straight lines connecting the points indicated by A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60) in the three component diagram defined by the apexes corresponding to each component.

The second side component contains in total about 15 parts by weight of at least one of Al₂ O₃ and ZrO₂ (the content of ZrO₂ is about 5 parts by weight or less) relative to 100 parts by weight of the oxide represented by SiO₂ --TiO₂ --XO.

The present invention according to a different aspect provides a monolithic ceramic capacitor provided with a plurality of dielectric ceramic layers, inner electrodes formed between the ceramic layers and outer electrodes electrically connected to the inner electrodes, wherein the dielectric ceramic layers are constructed by the dielectric ceramic composition described above and the inner electrodes are composed of nickel or a nickel alloy.

The outer electrode may be provided with a sintered layer of an electroconductive metal powder or an electroconductive metal powder supplemented with glass frits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view showing the monolithic ceramic capacitor according to one embodiment of the present invention.

FIG. 2 is a plane view showing the dielectric ceramic layer portion having inner electrodes of the monolithic ceramic capacitor shown in FIG. 1.

FIG. 3 is a disassembled perspective view showing the ceramic monolithic portion of the monolithic ceramic capacitor shown in FIG. 1.

FIG. 4 is a three component phase diagram of Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO oxides.

FIG. 5 is a three component phase diagram of SiO₂ --TiO₂ --XO oxides.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The basic construction of the monolithic ceramic capacitor according to the first embodiment of the present invention will be described hereinafter referring to the drawings. FIG. 1 is a cross section showing one example of the monolithic ceramic capacitor, FIG. 2 is a plane view showing the dielectric ceramic portion having inner electrodes of the monolithic ceramic capacitor in FIG. 1, and FIG. 3 is a disassembled perspective view showing the dielectric ceramic portion having inner electrodes of the monolithic ceramic capacitor in FIG. 1.

As shown in FIG. 1, the monolithic ceramic capacitor 1 according to the present embodiment is provided with a rectangular shaped monolithic ceramic body 3 obtained by laminating a plurality of dielectric ceramic layers 2a and 2b via inner electrodes 4. An outer electrode 5 is formed on both side faces of the monolithic ceramic body 3 so that the outer electrodes are electrically connected to each of the specified inner electrodes 4, on which a first plating layer 6 comprising nickel or copper is plated, and a second plating layer 7 comprising a solder or tin being further formed on the first plating layer.

The method for producing the monolithic ceramic capacitor 1 will be next described in the order of production steps.

At first, a raw material powder of barium titanate prepared by weighing and mixing in a given composition ratio is prepared as an essential component of the dielectric ceramic layers 2a and 2b.

Then, a slurry is prepared by adding an organic binder in this raw material powder and, after forming this slurry into a sheet, a green sheet for use in the dielectric ceramic layers 2a and 2b is obtained.

Next, an inner electrode 4 comprising nickel or a nickel alloy is formed on one principal face of the green sheet to serve as a dielectric ceramic layer 2b. Nickel or nickel alloys as base metals may be used for the material of the inner electrode 4 when the dielectric ceramic layers 2a and 2b are formed using the dielectric ceramic composition as described above but the invention is not limited thereto. The inner electrode 4 may be formed by a screen printing method, a deposition method or a plating method.

After laminating a required number of the green sheets for use in the dielectric ceramic layers 2b having the inner electrode 4, the green sheets are inserted between the green sheets having no inner electrode for use as the dielectric ceramic layers 2a, thus obtaining a raw monolithic body by press-adhering these green sheets. Then, this raw monolithic body is fired at a given temperature to obtain a ceramic monolithic body 3.

The outer electrodes 5 are formed at the both side faces of the ceramic monolithic body 3 so as to be electrically connected to the inner electrodes 4. The same material used in the inner electrodes 4 can be used for the outer electrodes 5. While silver, palladium, a silver-palladium alloy, copper and a copper alloy are available in addition to a composition prepared by adding a glass frit such as a B₂ O₃ --SiO₂ --BaO glass or Li₂ O--SiO₂ --BaO glass to these metal powders, an appropriate material should be selected by taking the application and application site of the monolithic capacitor into consideration. While the outer electrodes 5 can be formed by coating the ceramic monolithic body 3 obtained by firing with a metal powder paste as a raw material followed by heat-adhering, it may also be formed by heat-adhering the metal powder paste simultaneously with the ceramic monolithic body 3.

The first plating layer 6 is then formed by applying a plating of nickel or copper on the outer electrode 5. Finally, the second plating layer 7 comprising a solder or tin is formed on the first plating layer 6, thereby completing the monolithic capacitor 1. Such process for further forming a conductive layer on the outer electrode 5 may be omitted depending on the intended application of the monolithic ceramic capacitor.

By using the dielectric ceramic composition as described previously for constructing the dielectric ceramic layers 2a and 2b, the characteristics of the dielectric ceramic layers are not deteriorated even when it is fired in a reducing atmosphere. In other words, such characteristics are obtained in which the product the insulation resistance and the electrostatic capacitance (the product CR) is as high as about 4900 to 5000 Ω•F or more and about 200 Ω•F or more at room temperature and 150° C., respectively, when the capacitor is used under an electric field strength as high as about 10 kV/mm, while having a small voltage dependence of the insulation resistance, the absolute value of the capacitance decreasing ratio at an impressed DC voltage of 5 kV/mm being as small as about 40% to 45%, the insulation durability being as high as about 12 kV/mm or more under an AC voltage and about 14 kV/mm under a DC voltage, the temperature characteristics of the electrostatic capacitance satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C. and having excellent weather resistance performance as shown by a high temperature load test at 150° C. and at DC 25 kV/mm and a high humidity load test.

It has been confirmed that, among alkaline earth metal oxides such as SrO and CaO existing in barium titanate as impurities, alkali metal oxides such as Na₂ O and K₂ O and other oxides such as Al₂ O₃ and SiO₂, the content of the alkali metal oxides especially influences the electric characteristics. While the specific dielectric constant is decreased when the amounts of addition of rare earth element oxides such as Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, and Yb₂ O₃, and Sc₂ O₃ and Y₂ O₃ are increased, the specific dielectric constant can be kept to a practically acceptable range of about 900 to 1600 by keeping the content of the alkali metal oxides contained in barium titanate as impurities to about 0.02% by weight or less, preferably 0.012% or less.

Adding an oxide represented by Li₂ O--(Si, Ti)O₂ --MO (wherein MO is at least one of Al₂ O₃ and ZrO₂) to the dielectric ceramic composition allows the composition to be sintered at a relatively low temperature of about 1300° C. or less, further improving the high temperature load characteristic.

Adding an oxide represented by Si₂ O--TiO₂ --XO (wherein XO is at least one of BaO, CaO, SrO, MgO, ZnO and MnO) to the dielectric ceramic composition allows the composition to be improved in sintering property as well as in high temperature load characteristics and humidity resistance load characteristics. A higher insulation resistance can be obtained by adding Al₂ O₃ and/or ZrO₂ in the oxide represented by Si₂ O--TiO₂ --XO.

EXAMPLES

The present invention will now be described in more detail by way of examples. However, the present invention is not limited to these examples.

Example 1

After preparing and weighing TiCl₄ and Ba(NO₃)₂ having a variety of purity as starting materials, the compounds were precipitated as titanyl barium oxalate (BaTiO(C₂ O₄)•4H₂ O) by adding oxalic acid. This precipitate was decomposed by heating at a temperature of 1000° C. or more to synthesize four kinds of barium titanate listed in TABLE 1.

                  TABLE 1                                                          ______________________________________                                         Content of impurities (% by weight)                                                   Alkali                           Mean                                   Kind of                                                                               metal                            particle size                          BaTiO.sub.3                                                                           oxide   SrO     CaO  SiO.sub.2                                                                            Al.sub.2 O.sub.3                                                                     (μm)                                ______________________________________                                         A      0.003   0.012   0.001                                                                               0.01  0.005 0.6                                    B      0.02    0.01    0.003                                                                               0.019 0.008 0.56                                   C      0.012   0.179   0.018                                                                               0.155 0.071 0.72                                   D      0.062   0.014   0.001                                                                               0.019 0.004 0.58                                   ______________________________________                                    

Oxides, carbonates or hydroxides of each component of the first side component were weighed so as to be in a composition ratio (mole ratio) of 0.25Li₂ O-0.65(0.30TiO₂ •0.70SiO₂)-0.10Al₂ O₃ to obtain a powder by crushing and mixing.

Likewise, oxides, carbonates or hydroxides of each component of the second side component were weighed so as to be in a composition ratio (mole ratio) of 0.66SiO₂ -0.17TiO₂ -0.15BaO-0.02MnO to obtain a powder by crushing and mixing.

Oxide powders of the first and second side components were placed in separate platinum crucibles and heated at 1500° C. After quenching and crushing the mixture, each oxide powder with a mean particle size of 1 μm or less was obtained.

In the next step, BaCO₃ for adjusting the mole ratio Ba/Ti (m) in the barium titanate, and Sc₂ O₃, Y₂ O₃, Eu₂ O₃, Gd₂ O₃, Tb₂ O₃ and Dy₂ O₃, BaZrO₃, MgO and MnO, each having a purity of 99% or more, were prepared. These raw material powders and the oxides side components were weighted so as to form the compositions shown in TABLE 2 and TABLE 3. The amounts of addition of the first and second side components are indicated by parts by weight relative to 100 parts by weight of the essential component (BaO)_(m) TiO₂ +αM₂ O₃ +βR₂ O₃ +γBaZrO₃ +gMnO+hMnO.

An organic solvent such as polyvinyl butyral binder and ethanol were added to the weighed compounds and the resulting mixture was mixed in a ball mill in an wet state to prepare a ceramic slurry. This ceramic slurry was formed into a sheet by the doctor blade method to obtain a rectangular shaped green sheet with a thickness of 35 μm, followed by printing an electroconductive paste mainly composed of Ni on the ceramic green sheet to form an electroconductive paste layer for forming inner electrodes.

Then, a plurality of the ceramic green sheets on which the electroconductive layer had been formed were laminated so that the sides where the electroconductive paste is projected are alternately placed with each other, thus obtaining a monolithic body. This monolithic body was heated at 350° C. in a N₂ atmosphere and, after allowing the binder to decompose, the monolithic body was fired at the temperatures shown in TABLE 4 and TABLE 5 in a reducing atmosphere comprising H₂ --N₂ --H₂ O gases under an oxygen partial pressure of 10⁻⁹ to 10¹² MPa, thereby obtaining a ceramic sintered body.

Both side faces of the ceramic sintered body were coated with a silver paste containing B₂ O₃ --Li₂ --SiO₂ --BaO glass frit and fired at a temperature of 600° C. in a N₂ atmosphere, thereby obtaining outer electrodes electrically connected to the inner electrodes.

    TABLE 2        -   Amount of         Amount of addition of        (BaO).sub.m.TiO.sub.2 + αM.sub.2 O.sub.3 + βR.sub.2 O.sub.3        + γBaZrO.sub.3 + gMgO +       hMnO addition of the second               Sample Kind of α Total      of β  the first side side        No. BaTiO.sub.3 Sc.sub.2 O.sub.3 Y.sub.2 O.sub.3 α Eu.sub.2      O.sub.3 Gd.sub.2 O.sub.3 Tb.sub.2 O.sub.3 Dy.sub.2 O.sub.3 Total of      β α + β γ g h g +       h m component component         *1 A 0 0.0008 0.0008 0 0.05 0 0 0.05 0.0508 0.02 0.05 0.07 0.12 1.005      1  0         *2 A 0.03 0.03 0.06 0 0 0.001 0 0.001 0.061 0.03 0.04 0.08 0.12 1.005        1 0         *3 A 0.01 0.01 0.02 0 0 0.0008 0 0.0008 0.0208 0.03 0.02 0.03 0.05      1.005 1 0         *4 A 0 0.001 0.001 0 0.03 0.02 0.02 0.07 0.071 0.03 0.03 0.1 0.13      1.01 1 0         *5 A 0.01 0.02 0.03 0.02 0 0 0.02 0.04 0.07 0.03 0.12 0.01 0.13 1.01      1 0         *6 A 0.01 0.01 0.02 0 0.02 0.02 0 0.04 0.06 0 0.07 0.06 0.13 1.01 1.5        0         *7 A 0 0.01 0.01 0 0 0 0.02 0.02 0.03 0.08 0.03 0.04 0.07 1.01 1.5 0         *8 A 0.01 0.02 0.03 0 0 0.01 0.01 0.02 0.05 0.02 0.001 0.069 0.07      1.01 1 0         *9 A 0.01 0 0.01 0.01 0 0 0 0.01 0.02 0.02 0.125 0.005 0.13 1.01 1 0        *10 A 0.01 0.01 0.02 0.01 0.01 0 0 0.02 0.04 0.02 0.079 0.001 0.08      1.01 1 0        *11 A 0.01 0 0.01 0 0.01 0 0.01 0.02 0.03 0.02 0.005 0.13 0.13 1.01 1        *12 A 0.01 0.02 0.03 0.02 0 0 0.02 0.04 0.07 0.03 0.05 0.08 0.14 1.01      1 0        *13 A 0.005 0.005 0.01 0 0.01 0.01 0 0.02 0.03 0.03 0.03 0.025 0.055      0.99 1 0        *14 A 0.01 0 0.01 0.01 0.005 0.005 0.01 0.03 0.04 0.04 0.04 0.03 0.07      1.00 1 0        *15 A 0.005 0.005 0.01 0 0 0.01 0 0.01 0.02 0.04 0.02 0.03 0.05 1.038      1 0        *16 A 0.01 0 0.01 0.01 0 0 0.01 0.02 0.03 0.02 0.03 0.02 0.05 1.05 0 1        *17 A 0 0.01 0.01 0 0 0.01 0.01 0.02 0.03 0.02 0.03 0.04 0.07 1.01 0 0        *18 A 0 0.01 0.01 0 0.01 0.01 0.01 0.03 0.04 0.02 0.04 0.03 0.07 1.01      5 0        *19 A 0 0.01 0.01 0.01 0.01 0 0 0.02 0.03 0.02 0.02 0.04 0.06 1.01 0 0        *20 A 0.01 0.01 0.02 0 0 0.01 0 0.01 0.03 0.02 0.03 0.02 0.05 1.01 0 4        *21 D 0 0.01 0.01 0 0.01 0.02 0 0.03 0.04 0.03 0.04 0.05 0.09 1.01 2 0         22 A 0 0.001 0.001 0.02 0 0.009 0 0.029 0.03 0.02 0.04 0.01 0.05      1.015 1 0         23 B 0.01 0.01 0.02 0 0.01 0 0 0.01 0.03 0.03 0.03 0.02 0.05 1.02 1

    TABLE 3        -   Amount of         Amount of addition of        (BaO).sub.m.TiO.sub.2 + αM.sub.2 O.sub.3 + βR.sub.2 O.sub.3        + γBaZrO.sub.3 + gMgO +       hMnO addition of the second               Sample Kind of α Total      of β  the first side side        No. BaTiO.sub.3 Sc.sub.2 O.sub.3 Y.sub.2 O.sub.3 α Eu.sub.2      O.sub.3 Gd.sub.2 O.sub.3 Tb.sub.2 O.sub.3 Dy.sub.2 O.sub.3 Total of      β α + β γ g h g +       h m component component        24 C 0.01 0.02 0.03 0 0 0 0.01 0.01 0.04 0.03 0.12 0.002 0.122 1.03 1        25 A 0.01 0.03 0.04 0 0 0.01 0 0.01 0.05 0.03 0.07 0.06 0.13 1.02 1 0        26 A 0.01 0.04 0.05 0 0.01 0 0 0.01 0.06 0.03 0.002 0.12 0.122 1.01 0      1        27 A 0.005 0.005 0.01 0 0 0 0.001 0.001 0.011 0.02 0.01 0.02 0.03 1.01        1 0        28 A 0 0.01 0.01 0.01 0.01 0 0 0.02 0.03 0.02 0.03 0.02 0.05 1.01 1 0        29 A 0 0.01 0.01 0.02 0 0.01 0 0.03 0.04 0.02 0.05 0.03 0.08 1.015 0 1        30 A 0 0.01 0.01 0 0.04 0 0 0.04 0.05 0.02 0.06 0.03 0.09 1.01 0 1           31 A 0 0.01 0.01 0 0.03 0 0.02 0.05 0.06 0.02 0.05 0.06 0.11 1.01 1        0        32 A 0.01 0.02 0.03 0 0 0.02 0 0.02 0.05 0.02 0.05 0.04 0.09 1.01 1 0        33 A 0.01 0.02 0.03 0 0 0 0.03 0.03 0.06 0.03 0.06 0.04 0.1 1.01 1 0         34 A 0 0.01 0.01 0 0.02 0 0 0.02 0.03 0.01 0.03 0.02 0.05 1.01 1 0          35 A 0.01 0.01 0.02 0.02 0 0 0 0.02 0.04 0.04 0.05 0.03 0.08 1.01 1        36 A 0.01 0.01 0.02 0 0.01 0.01 0 0.02 0.04 0.06 0.05 0.02 0.07 1.01 1        0        37 A 0.01 0.01 0.02 0 0 0.01 0.01 0.02 0.04 0.03 0.04 0.03 0.07 1.01 2        0        38 A 0.01 0.01 0.02 0.01 0 0 0 0.01 0.03 0.03 0.04 0.015 0.055 1.01 2        39 A 0.01 0.01 0.02 0 0.01 0 0 0.01 0.03 0.02 0.03 0.04 0.07 1.01 2 0        40 A 0 0.02 0.02 0 0 0.01 0 0.01 0.03 0.02 0.03 0.02 0.05 1.01 2 0           41 A 0 0.02 0.02 0 0 0 0.01 0.01 0.03 0.02 0.03 0.03 0.06 1.001 2 0        42 A 0.02 0 0.02 0.01 0.01 0 0 0.02 0.04 0.03 0.04 0.03 0.07 1.01 0 2        43 A 0.01 0.01 0.02 0 0 0.01 0.01 0.02 0.04 0.03 0.03 0.05 0.08 1.035      2 0        44 A 0.01 0.01 0.02 0 0.02 0 0 0.02 0.04 0.03 0.04 0.03 0.07 1.015 0.2        0        45 A 0.01 0.01 0.02 0 0 0 0.01 0.01 0.03 0.03 0.03 0.02 0.05 1.01 3 0        46 A 0 0.02 0.02 0 0 0 0.01 0.01 0.03 0.03 0.02 0.04 0.06 1.01 0 0.2         47 A 0 0.02 0.02 0.01 0 0.01 0 0.02 0.04 0.03 0.05 0.02 0.07 1.01 0      3

The overall dimensions of the monolithic ceramic capacitor thus obtained were 5.0 mm in width, 5.7 mm in length and 2.4 mm in thickness while the thickness of each dielectric ceramic layer was 30 μm. The total number of the effective dielectric ceramic layers were 57, the area of the confronting electrode per layer being 8.2×10⁻⁶ m².

Electric characteristics of these monolithic ceramic capacitors were measured. The electrostatic capacitance (C) and dielectric loss (tan δ) were measured using an automatic bridge type measuring instrument at 1 kHz, 1 Vrms and 25° C. and the dielectric constant (ε) was calculated from the electrostatic capacitance. Next, the insulation resistance was measured using an insulation resistance tester at 25° C. and 150° C. by impressing direct current voltages of 315 V (or 10 kV/mm) and 945 V (or 30 kV/mm) for 2 minutes, obtaining the product of the electrostatic capacitance and insulation resistance, or the product CR.

The rate of change of the electrostatic capacitance against temperature changes was also measured. The rate of change at -25° C. and 85° C. by taking the electrostatic capacitance at 20° C. as a standard (ΔC/C₂₀), the rate of change at -55° C. and 125° C. by taking the electrostatic capacitance at 25° C. as a standard (ΔC/C₂₅) and the maximum value of the rate of change (|ΔC|_(max)) as an absolute value were measured as the electrostatic capacitances against temperature changes.

The DC vias characteristic was also evaluated. First, the electrostatic capacitance when an AC voltage of 1 kHz and 1 Vrms was impressed was measured. Then, the electrostatic capacitance when a DC voltage of 150 V and an AC voltage of 1 kHz and 1 Vrms were simultaneously impressed was measured, thereby the rate of reduction of the electrostatic capacitance (ΔC/C) due to loading the DC voltage was calculated.

In the high temperature load test, a direct current voltage of 750 V (or 25 kV/mm) was impressed at 150° C. on 36 pieces of each sample to measure the time dependent changes of the insulation resistance. The time when the insulation resistance of each sample was reduced below 10⁶ Ω was defined to be a life span time and mean life span time was evaluated.

In the humidity resistance test, the number of the test pieces having an insulation resistance of 10⁶ Ω or less among the 72 test pieces were counted after impressing a DC voltage of 315 V under an atmospheric pressure of 2 atm (relative humidity 100%) at 120° C. for 250 hours.

Insulation breakdown voltages under AC and DC voltages were measured by impressing AC and DC voltages at a voltage increase rate of 100 V/sec.

The results described above are listed in TABLE 4 and TABLE 5.

    TABLE 4        - DC vias Product CR (Ω ·       F)  Humidity                      Ratio of Temperature Dependent      Capacitor characteristic 315 V 945 V 315 V 945 V Insulation breakdown      Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test:        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Mean Life        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC rejects Span         *1 1300 1210 0.7 5.6 -12 6.4 -17.5 21 -21 5110 4860 220 210 12 14      0/72 960         *2 1300  960 0.7 2.3 -7.8 4.7 -6.9 8.7 -16 8520 8090 200 190 12 14      0/72 910         *3 1300 1550 0.7 3 -7.9 5 -6.8 8.5 -42 3020 2870 120 110 13 14 0/72      930         *4 1300  920 0.7 6 -12.9 7.5 -19 25.3 -14 5060 4810 250 240 12 14      0/72 120         *5 1280  960 2 2.1 -8 4.2 -7.1 8.5 -14 5070 4820 260 250 12 14 10/72        180         *6 1280 1070 0.7 1.9 -8.2 3 -7.5 8.9 -16 3120 2180 140 100 12 14 0/72        870         *7 1300 1440 0.7 2.2 -14.3 4.5 -31.5 36.2 -36 5160 4900 240 230 12 14        0/72 160         *8 1280 1280 0.8 2.2 -12.5 4.6 -16.3 21.3 -26 3090 2940 130 120 13 14        0/72 950         *9 1360 1530 2.6 2.3 -7.7 5 -7.5 8.5 -43 5110 4860 230 220 12 14      53/72        120                                                                *10      U nmeasurable Due to Semiconductor Formation        *11 1280 1460 0.7 3 -8.5 5.1 -17.9 23.6 -38 3150 2990 150 140 12 14      0/72 150        *12 1280  940 2.1 2.3 -8.2 4.5 -8.5 8.7 -14 5060 4800 240 230 12 14      9/72 100        *13 Unmeasurable Due to Semiconductor Formation        *14 1300 1360 0.7 3.4 -8.4 5.3 -8 9.3 -30 3200 3040 160 150 10 11 0/72      1 30        *15 Unmeasurable Due to Insufficient Sintering        *16 Unmeasurable Due to Insufficient Sintering        *17 Unmeasurable Due to Insufficient Sintering        *18 1300 1320 2.6 3.3 -8.3 5.1 -8.2 9.2 -25 3250 3090 170 160 11 12      0/72 150        *19 Unmeasurable Due to Insufficient Sintering        *20 1300 1470 2.6 1.9 -8.7 4 -8 9.3 -41 3300 3140 180 170 12 12 0/72      110        *21 1300 1140 0.6 2.2 -8.9 7 -8.3 9.5 -26 5180 4920 280 270 12 14 0/72        860         22 1280 1480 0.7 5.2 -7.2 6.5 -7 8.7 -39 5090 4840 270 260 12 15 0/72        920         23 1280 1460 0.7 1.6 -7.6 7 -7.2 8.8 -39 5020 4770 250 240 12 14 0/72        940

    TABLE 5        - DC vias Product CR (Ω ·       F)  Humidity                      Ratio of Temperature Dependent      Capacitor characteristic 315 V 945 V 315 V 945 V Insulation breakdown      Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test:        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Mean Life        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject Span        24 1280 1350 0.6 1.7 -8.5 5.9 -7.8 8.9 -31 5280 5020 290 280 12 15      0/72 990        25 1300 1260 0.6 2 -8.7 5.1 -8.2 9.5 -23 5130 4870 270 260 12 14 0/72      890        26 1300 1080 0.7 2.1 -8.8 5.5 -8.3 9.2 -17 5200 4940 220 210 12 15      0/72 950        27 1300 1650 0.6 2.1 -7.5 6.1 -7.5 8.7 -45 5210 4950 230 220 12 14      0/72 820        28 1300 1410 0.7 3 -7.9 6.7 -7.3 8.8 -36 5290 5030 280 270 12 14 0/72      850        29 1280 1370 0.6 3.1 -8.2 6 -7.8 8.8 -33 5200 4940 290 280 13 14 0/72      900        30 1280 1230 0.6 2.1 -8.5 5.8 -7.9 9.5 -22 5260 5000 250 240 12 14      0/72 870        31 1300 1030 0.6 2 -8.9 5 -8.2 9.2 -15 5240 4980 210 200 12 14 0/72      920        32 1300 1260 0.6 1.9 -7.9 4.8 -7.5 8.7 -21 5010 4760 200 190 12 14      0/72 920        33 1300 1060 0.6 2 -8 4.9 -7.8 8.5 -16 5230 4970 260 250 12 14 0/72      870        34 1280 1420 0.6 2 -8.2 5.3 -7.9 8.9 -36 5060 4810 280 270 12 14 0/72      850        35 1280 1360 0.6 2 -7.8 5.7 -8 8.6 -30 5260 5000 230 220 12 15 0/72      820        36 1300 1370 0.7 2.5 -7.9 6 -7.6 8 -32 5100 4850 220 210 12 14 0/72      850        37 1300 1350 0.6 2 -8 6.1 -7.7 8.5 -32 5070 4820 250 240 12 14 0/72      890        38 1300 1470 0.6 2 -8.1 5.8 -8 8.6 -39 5090 4840 230 220 13 14 0/72      900        39 1280 1440 0.7 2.6 -8.1 5.9 -7.9 8.7 -39 5100 4850 240 230 13 14      0/72 870        40 1280 1480 0.7 2.5 -8.5 6 -8.2 9.2 -40 5210 4950 210 200 12 14 0/72      910        41 1280 1460 0.6 2 -7.8 6.7 -8 8.6 -40 5220 4960 260 250 12 14 0/72      890        42 1300 1380 0.6 2.7 -7.9 6 -8.2 8.7 -30 5160 4900 230 220 12 14 0/72      920        43 1300 1350 0.6 2 -8.1 5.8 -8 8.5 -30 5360 5090 250 240 12 14 0/72      900        44 1300 1320 0.6 2.5 -8.2 5.9 -7.7 8.9 -25 5180 4920 230 220 12 14      0/72 880        45 1300 1450 0.7 2.3 -8.3 7.2 -7.8 8.8 -38 5190 4930 290 280 12 14      0/72 850        46 1280 1430 0.7 2.3 -8 6.8 -7.9 8.8 -38 5230 4970 270 260 12 14 0/72      860        47 1300 1440 0.6 2.2 -7.9 6.5 -7.5 8 -38 5260 5000 260 250 12 14 0/72      920

It is evident from Table 1 to TABLE 5 that the monolithic ceramic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of less than 1.0 %, wherein the rate of change of the electrostatic capacitance against temperature changes satisfies both the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show values as high as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more in addition to enabling a relatively low firing temperature of 1300° C. or less.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +αM₂ O₃ +βR₂ O₃ +γBaZrO₃ +gMnO +hMgO (wherein M₂ O₃ represents at least one of Sc₂ O₃ or Y₂ O₃ and R₂ O₃ represents at least one of Eu₂ O₃, Gd₂ O₃, Tb₂ O₃ and Dy₂ O₃, α, β, γ, g and h representing mole ratio, respectively), a M₂ O₃ content α of less than about 0.001 as shown in the sample No. 1 is not preferable because the temperature characteristic does not satisfy the B-level/X7R characteristics. On the other hand, a M₂ O₃ content α of more than about 0.05 as shown in the sample No. 2 is also not preferable because the specific dielectric constant is reduced to less than 1000. Accordingly, the preferable range ofthe M₂ O₃ content α is 0.001≦α≦0.05.

It is not preferable that the R₂ O₃ content β is less than about 0.001 as in the sample No. 3 since the insulation resistance is so low that the product CR becomes small. It is also not preferable that the R₂ O₃ content β is more than about 0.05 as in the sample No. 4 because the temperature characteristic does not satisfy the B-level/X7R characteristics, reducing reliability. Accordingly, the preferable range of the R₂ O₃ content β is 0.001≦β≦0.05.

When the combined amount of M₂ O₃ and R₂ O₃ (α+β) is more than about 0.06, the dielectric loss is increased up to 2.0% while the mean life span is shortened, and the number of rejects in the humidity resistance load test is increased. Accordingly, the combined amount of M₂ O₃ and R₂ O₃ (α+β) is preferably in the range of α+≦0.06.

It is not preferable that, as seen in the sample No. 6, the BaZrO₃ content γ is zero since the insulation resistance becomes low while having a larger voltage dependency of the insulation resistance than in the system containing BaZrO₃. On the other hand, when the BaZrO₃ content γ exceeds about 0.06 as in the sample No. 7, the temperature characteristic does not satisfy the B-level/X7R characteristics, and the mean life span is shortened. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦γ≦0.06.

It is not preferable that, as seen in the sample No. 8, the MgO content g is about 0.001 since the insulation resistance becomes low and the temperature characteristics do not satisfy the B-level/X7R characteristics. On the other hand, when the MgO content g exceeds about 0.12 as seen in the sample No. 9, the sintering temperature becomes high and the dielectric loss exceeds 2.0%, which is not preferable because rejection in the humidity resistance test are greatly increased while shortening the mean life span. Accordingly, the preferable range of the MgO content g is 0.001≦g≦0.12.

It is not preferable that, as seen in the sample No. 12, the MnO content h is about 0.001 as seen in the sample No. 10 since the sample becomes not measurable due to semiconductor formation. It is not preferable that the MnO content h exceeds about 0.12, on the other hand, because the temperature characteristic X7R is not satisfied, the insulation resistance becomes low and the mean life span becomes short. Accordingly, the preferable MnO content h is in the range of 0.001<h≦0.12.

It is not preferable that, as seen in the sample No. 12, the combined content of MgO and MnO (g+h) exceeds about 0.13 because the dielectric loss is increased to 2.0%, the mean life span is shortened and the number of rejects in the humidity resistance load test is increased. Accordingly, the combined content of MgO and MnO (g+h) is preferably in the range of g+h≦0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 13 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample No. 14, that the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage become low along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m≦1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 17 and 19 because measruement are impossible due to insufficient sintering. When the amount of addition of the first or second side component exceeds about 3.0 parts by weight as seen in the samples No. 18 and 20, the dielectric loss exceeds 1.0% and the insulation resistance and insulation breakdown voltage are lowered along with shortening the mean life span, which are not preferable. Accordingly, the preferable content of either the first or the second components is about 0.2 to 3.0 parts by weight.

The content of the alkali earth metal oxides contained in barium titanate as impurities are below about 0.02% by weight because when the content of the alkali earth metal oxides exceeds about 0.02% by weight, the dielectric constant is decreased.

Example 2

A starting material BaO₁.010 •TiO₂ +0.010Y₂ O₃ +0.02Gd₂ O₃ +0.01BaZrO₃ +0.05MgO+0.01MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder, in which Li₂ O--(Si, Ti)O₂ --MO oxide with a mean particle size of 1 μm or less shown in TABLE 6 prepared by heating at 1200 to 1500° C. was added as a first side component. A monolithic ceramic capacitor was prepared by the same method as in Example 1, except that the starting material as described above was used. The overall dimensions of the monolithic ceramic capacitor produced are the same as in Example 1.

Then, the electric characteristics were measured by the same method as described above. The results are shown in TABLE 7.

                  TABLE 6                                                          ______________________________________                                         The first side component                                                              Amount of                                                                                addition                                                      Sample (parts by                                                                               Composition (mol % except w)                                   No.    weight)  Li.sub.2 O                                                                             (Si.sub.w Ti.sub.l-w)O.sub.2                                                           w    Al.sub.2 O.sub.3                                                                     ZrO.sub.2                           ______________________________________                                         101    1        20      80      0.3  0     0                                     102 1 10 80 0.6 5 5                                                            103 0.8 10 70 0.5 20 0                                                         104 0.8 35 45 1 10 10                                                          105 1.5 45 45 0.5 10 0                                                         106 1.5 45 55 0.3 0 0                                                          107 1 20 70 0.6 5 5                                                            108 1 20 70 0.4 10 0                                                           109 1.2 30 60 0.7 5 5                                                          110 1.2 30 60 0.8 10 0                                                         111 2 40 50 0.6 5 5                                                            112 2 40 50 0.9 0 10                                                           113 1.5 10 85 0.4 5 0                                                          114 2 5 75 0.6 10 10                                                           115 1.2 20 55 0.5 25 0                                                         116 1 45 40 0.8 0 15                                                           117 0.8 50 45 0.7 5 0                                                          118 1.2 25 75 0.9 0 0                                                          119 1.5 25 75 1 0 0                                                            120 1 35 65 0.9 0 0                                                            121 1.5 35 65 1 0 0                                                            122 1.2 20 70 0.2 0 10                                                       ______________________________________                                    

    TABLE 7        - DC vias Product CR (Ω ·       F)  Humidity                      Ratio of Temperature Dependent      Capacitor characteristic 315 V 945 V 315 V 945 V Insulation breakdown      Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC rejects (h)        101 1280 1480 0.6 2.1 -8.5 5.2 -8 8:3 -39 5090 4840 230 220 12 15 0/72      8 80        102 1280 1490 0.6 2.3 -8 5.6 -8.5 8.9 -40 5080 4830 240 230 12 14 0/72        850        103 1280 1420 0.6 3 -8.1 4.9 -8.9 9.5 -38 5070 4820 250 240 12 14 0/72        900        104 1300 1400 0.6 2.4 -8.3 5 -9.2 9.5 -36 5100 4850 230 220 12 15 0/72        910        105 1300 1460 0.6 2.6 -8 5.2 -9.5 9.7 -37 5120 4860 220 210 13 14 0/72        820        106 1280 1440 0.7 2.1 -8.9 4.8 -8.2 8.8 -37 5100 4850 230 220 12 14      0/72 820        107 1280 1500 0.6 2 -7.9 4.9 -9.1 9.5 -40 5230 4970 250 240 13 14 0/72        910        108 1280 1480 0.6 3.1 -7.8 5.2 -9.4 9.6 -40 5130 4870 240 230 12 14      0/72 930        109 1280 1480 0.6 2.8 -8.2 5.4 -9 9.2 -40 5090 4840 230 220 12 14 0/72        880        110 1300 1490 0.6 2.5 -8.2 5.5 -9.5 9.8 -40 5080 4830 220 220 12 14      0/72 860        111 1300 1460 0.6 2 -8.5 5.7 -9.1 9.5 -39 5070 4820 220 210 12 14 0/72        880        112 1280 1470 0.6 2.8 -8 5 -9 9.2 -39 5130 4870 220 210 12 14 0/72 870        113 1350 Unmeasurable due to Insufficent Sintering        114 1350 Unmeasurable due to Insufficient Sintering        115 1350 1450 1.4 2.2 -8.9 4.8 -8.7 9   -39 5160 4900 250 240 11 13      20/72        120                                                                116      1 350 Unmeasurable due to Insufficient Sintering        117 1350 Unmeasurable due to Insufficient Sintering        118 1300 1450 0.6 2.3 -8.8 5.3 -8.9 9.2 -39 5200 4940 240 230 12 14      0/72 820        119 1350 1490 1.3 1.9 -8.5 4.5 -8.6 8.9 -40 5190 4930 260 250 11 13      11/72        190                                                                120        1300 1440 0.6 2.4 -9.2 5 -9.2 9.3 -37 5180 4920 250 240 12 14 0/72 860        121 1350 1460 1.3 2.l -8.8 4.2 -8.7 9   -37 5170 4910 240 230 11 13      22/72        120                                                                122        1350 1450 1.2 2.2 -8.7 4.5 -8.8 9.2 -37 5200 4940 230 220 11 13 19/72        170

As is evident from TABLE 6 and TABLE 7, preferable results are obtained in the samples No. 101 to 112, 118 and 120, in which oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting the spots indicated by A (X=20, y=80, z=0), B (X=10, y=80, z=10), C (X=10, y=70, z=20), D(X=35, y=45, z=20), E (X=45, y=45, z=10) and F (X=45, y=55, z=10) in the three component phase diagram of the oxides represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ -MO shown in FIG. 4 are added, wherein the samples have a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with a rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

The insulation resistance represented by the product CR at 25° C. and 150° C. shows values as high as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the capacitor used under a electric field strength of 10 kV/mmn. The insulation breakdown voltages are as high as 12 kV/mm or more under AC voltage and 14 kV/mm or more under a DC voltage. The mean life span is as long as 800 hours or more in the acceleration test at 150° C. and DC 25 kV/mm while using a relatively low firing temperature of 1300° C. or less.

On the contrary, when the Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO oxide is outside of the composition range described above, the sintering becomes insufficient or many samples are rejected in the humidity resistance load test even after sintering, as seen in the samples No. 113 to 117 and 119. With the samples with the composition falling on the line A-F and w=1.0 (samples No. 119 and 121) the sintering temperature becomes high along and there are many rejects in the humidity resistance load test. When the value of w is less than about 0.30 as shown in the sample No. 122, the sintering temperature becomes high along with having many rejects in the humidity resistance load test.

Example 3

A starting material BaO₁.010 •TiO₂ +0.010Y₂ O₃ +0.01Eu₂ O₃ +0.01Gd₂ O₃ +0.01BaZrO₃ +0.05MgO+0.01MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder, in which oxides represented by SiO₂ --TiO₂ --XO with a mean particle size of 1 μm or less shown in TABLE 8 prepared by heating at 1200 to 1500° C. was added as a second side component. A monolithic ceramic capacitor was produced by the same method as in Example 1, except that the starting material as described above was used. The amounts of addition of Al₂ O₃ and ZrO₂ correspond to the amounts of addition relative to 100 parts by weight of the second side component (xSiO₂ --yTiO₂ --zXO). The overall dimensions of the monolithic capacitor produced is the same as in Example 1.

Then, the electric characteristics were measured as in Example 1. The results are shown in TABLE 9.

                                      TABLE 8                                      __________________________________________________________________________     The second side component                                                          Amount of                                                                             Essential component (mole %)                                        Sample                                                                             addition (parts                                                                             XO                   Added component (Parts by weight)        No. by weight)                                                                            SiO.sub.2                                                                         TiO.sub.2                                                                         BaO                                                                               CaO                                                                               SrO                                                                               MgO                                                                               ZnO                                                                               MnO                                                                               Total                                                                             Al.sub.2 O.sub.3                                                                        ZrO.sub.2                       __________________________________________________________________________     201 1      85 1  1  0  0  0  4  9  14 0        0                                 202 1 35 51 0 10 0 0 0 4 14 0 0                                                203 1 30 20 0 30 0 15 4 1 50 0 0                                               204 1 39 1 20 20 2 0 13 5 60 0 0                                               205 1 70 10 5 5 0 0 10 0 20 0 0                                                206 1 45 10 0 0 0 0 15 30 45 0 0                                               207 1 50 20 10 10 3 7 0 0 30 0 0                                               208 1 50 30 0 16 0 0 0 4 20 0 0                                                209 1 35 30 25 10 0 0 0 0 35 0 0                                               210 1 40 40 10 0 0 0 5 5 20 0 0                                                211 1 45 22 3 30 0 0 0 0 33 15 0                                               212 1 45 22 3 30 0 0 0 0 33 10 5                                               213 1 65 25 5 5 0 0 0 0 10 0 0                                                 214 1 25 40 15 0 10 0 5 5 35 0 0                                               215 1 30 10 30 25 0 0 5 0 60 0 0                                               216 1 50 0 35 15 0 0 0 0 50 0 0                                                217 1 45 22 30 0 0 3 0 0 33 25 0                                               218 1 45 22 30 0 3 0 0 0 33 0 15                                               219 1 30 60 10 0 0 0 0 0 10 0 0                                              __________________________________________________________________________

    TABLE 9        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitor characteristic 315 V      945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        201 1300 1460 0.6 3.2 -8.2 6.8 -7.9 8.5 -39 5080 4830 220 210 12 14      0/72 840        202 1280 1490 0.6 3.5 -8.4 7 -8.1 8.6 -40 5080 4830 230 220 12 14 0/72        800        203 1280 1470 0.6 4 -8.6 7.2 -8.3 8.7 -39 5120 4860 220 210 12 14 0/72        920        204 1300 1450 0.6 3.8 -8.5 6.9 -8.2 8.6 -39 5150 4890 240 230 12 14      0/72 860        205 1300 1460 0.6 3.9 -8.5 7.1 -8.2 8.8 -39 5070 4820 220 210 12 14      0/72 820        206 1280 1430 0.6 3.7 -8.5 6.8 -8.3 8.7 -38 5080 4830 220 210 13 15      0/72       90                                                                  207        1280 1450 0.6 3.5 -8.4 7 -8.1 8.7 -39 5030 4780 230 220 12 14 0/72 890        208 1300 1470 0.6 3.1 -8 6.7 -7.9 8.3 -39 5040 4790 200 190 12 14 0/72        930        209 1300 1460 0.6 3.5 -8.4 6.9 -8 8.7 -39 5080 4830 220 210 12 14 0/72        830        210 1280 1450 0.6 3.9 -8.6 7.2 -8.2 8.8 -39 5100 4850 210 200 12 14      0/72 860        211 1300 1430 0.6 4 -8.7 7.3 -8.5 8.9 -38 5410 5140 300 290 12 14 0/72        870        212 1350 1440 0.6 3.8 -8.4 6.9 -8 8.7 -39 5420 5150 310 300 12 14 0/72        880        213 1350 1420 1.2 3.1 -8.1 6.6 -7.6 8.3 -38 5120 4860 230 220 11 13      38/72        150                                                                214      1 350 Unmeasurable due to insufficient sintering        215 1350 Unmeasurable due to insufficient sintering        216 1350 1420 1.3 3.3 -8.2 6.8 -7.8 8.5 -38 5030 4780 220 210 11 13      70/72        120                                                                217      1 350 Unmeasurable due to insufficient sintering        218 1350 Unmeasurable due to insufficient sintering        219 1350 Unmeasurable due to insufficient sintering

As is evident from TABLE 8 and TABLE 9, preferable results are obtained in samples No. 201 to 212 in which oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting the spots indicated by A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60), wherein x, y and z represent mole %, in the three component phase diagram of the SiO₂ --TiO₂ --XO oxides shown in FIG. 5 are added, wherein the samples have a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

When the capacitor is used under a high electric field strength of 10 kV/mm, the insulation resistance represented by the product CR at 25° C. and 150° C. show a high value of 5000 Ω•F or more and 200 Ω•F or more, respectively. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. The mean life span in the acceleration test at 150° C. and DC 25 l(V/mn is as long as 800 hours along with being free from rejects in the humidity resistance load test and it was possible to sinter the material at a relatively low sintering temperature of 1300° C.

In other SiO₂ --TiO₂ --XO oxides, on the other hand, sintering becomes insufficient as in samples No. 213 to 219 or rejects occurred in the humidity resistance load test even after sintering.

Although a monolithic capacitor having 5400 Ω•F or more and 300 Ω•F or more of the insulation resistances at 25° C. and 150° C., respectively, under the electric field strength of 10 kV/mm were obtained, the sintering property is extremely deteriorated when the amounts of addition of Al₂ O₃ and ZrO₂ exceed about 15 parts by weight and about 5 parts by weight, respectively.

Example 4

The four kinds of barium titanate (BaTiO₃) in TABLE 1, an oxide powder as a first side component and an oxide powder as a second side component were obtained by the same method as in Example 1.

Next, BaCO₃ for adjusting the Ba/Ti mole ratio m of barium titanate, and Sc₂ O₃, Y₂ O₃, Eu₂ O₃, Gd₂ O₃, Tb₂ O₃ and Dy₂ O₃, BaZrO₃ and MnO, each having a purity of 99% or more, were prepared. These raw material powders and the foregoing oxide powder as one of the side component of either the first or the second component were weighed to be the compositions shown in TABLE 10 and TABLE 11. The amounts of addition of the first and second side components correspond to the amount of addition relative to 100 parts by weight of the essential component (BaO)_(m) TiO₂ +αM₂ O₃ +βR₂ O₃ +(BaZrO₃ +gMnO). A monolithic ceramic capacitor was produced using this weighed materials by the same method as in Example 1. Overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 1.

The electric characteristics were measured by the same method as in Example 1. The results are shown in TABLE 12 and TABLE 13.

    TABLE 10        -  The amount of The amount of addition        (BaO).sub.m.TiO.sub.2 + αM.sub.2 O.sub.3 + βR.sub.2 O.sub.3        + γBaZrO.sub.3 + gMnO addition of the first of the second side         Sample Kind of α  β Total of  side component component      (parts by        No. BaTiO.sub.3 Sc.sub.2 O.sub.3 Y.sub.2 O.sub.3 Total of α      Eu.sub.2 O.sub.3 Gd.sub.2 O.sub.3 Tb.sub.2 O.sub.3 Dy.sub.2 O.sub.3      β α +       β γ g m (parts by weight) weight)        *301 A 0 0.0007 0.0007 0.04 0 0 0 0.04 0.0407 0.03 0.09 0.01 1.5 0           *302 A 0.05 0.02 0.07 0 0.001 0.001 0 0.002 0.072 0.02 0.14 1.005      1.2 0        *303 A 0.02 0 0.02 0 0 0 0.0008 0.0008 0.0208 0.03 0.04 1.015 1 0            *304 A 0 0.001 0.001 0.04 0 0.03 0 0.07 0.071 0.04 0.14 1.005 1 0        *305 A 0 0.04 0.04 0 0.02 0.02 0 0.04 0.08 0.03 0.16 1.005 1 0               *306 A 0.01 0 0.01 0.01 0 0 0.02 0.03 0.04 0 0.08 1.01 1.5 0          *307 A 0 0.01 0.01 0 0 0.02 0 0.02 0.03 0.08 0.06 1.01 1.5 0               *308 A 0.01 0.01 0.02 0 0.02 0 0 0.02 0.04 0.01 0.001 1.005 1 0        *309 A 0 0.01 0.01 0.01 0 0 0 0.01 0.02 0.02 0.14 1.01 1 0        *310 A 0.01 0 0.01 0 0 0 0.02 0.02 0.03 0.03 0.06 0.99 1.2 0        *311 A 0 0.02 0.02 0 0.01 0.01 0.01 0.03 0.05 0.03 0.1 1.00 1 0              *312 A 0.005 0.005 0.01 0 0.03 0 0 0.03 0.04 0.04 0.08 1.038 1 0        *313 A 0 0.01 0.01 0 0 0 0.03 0.03 0.04 0.03 0.08 1.05 0 2        *314 A 0.02 0 0.02 0.01 0.01 0 0 0.02 0.04 0.03 0.09 1.005 0 0               *315 A 0 0.01 0.01 0.01 0 0 0.02 0.03 0.04 0.02 0.08 1.01 5 0         *316 A 0.01 0 0.01 0 0 0.01 0.01 0.02 0.03 0.02 0.06 1.01 0 0               *317 A 0.02 0 0.02 0.02 0 0 0 0.02 0.04 0.03 0.08 1.015 0 4           *318 D 0.01 0 0.01 0 0 0 0.03 0.03 0.04 0.03 0.08 1.01 2.5 0               319 A 0 0.001 0.001 0.01 0.01 0.01 0 0.03 0.031 0.02 0.06 1.015        1 0       320 B 0 0.02 0.02 0 0 0 0.01 0.01 0.03 0.02 0.06 1.01 1 0        321 C 0.01 0.01 0.02 0.01 0 0.02 0 0.03 0.05 0.03 0.11 1.01 1 0               322 A 0.01 0.03 0.04 0 0 0 0.01 0.01 0.05 0.02 0.1 1.005 1

    TABLE 11        -  The amount of The amount of addition        (BaO).sub.m.TiO.sub.2 + αM.sub.2 O.sub.3 + βR.sub.2 O.sub.3        + γBaZrO.sub.3 + gMnO addition of the first of the second side         Sample Kind of α  β Total of  component (parts component      (parts by        No. BaTiO.sub.3 Sc.sub.2 O.sub.3 Y.sub.2 O.sub.3 Total of α      Eu.sub.2 O.sub.3 Gd.sub.2 O.sub.3 Tb.sub.2 O.sub.3 Dy.sub.2 O.sub.3      β α +       β γ g m by weight) weight)        323 A 0 0.05 0.05 0.01 0 0 0 0.01 0.06 0.03 0.13 1.01 0 1        324 A 0.02 0.01 0.03 0 0.001 0 0 0.001 0.031 0.02 0.06 1.005 1 0             325 A 0.02 0 0.02 0 0 0 0.02 0.02 0.04 0.03 0.08 1.01 1.1 0             326 A 0 0.01 0.01 0.01 0 0.02 0 0.03 0.04 0.02 0.08 1.01 0 1            327 A 0.01 0 0.01 0 0 0.01 0.02 0.03 0.04 0.03 0.08 1.01 0 2             328 A 0.01 0 0.01 0.03 0.02 0 0 0.05 0.06 0.02 0.12 1.01 1 0            329 A 0.01 0.01 0.02 0.02 0 0 0 0.02 0.04 0.02 0.08 1.005 1 0            330 A 0.01 0.02 0.03 0 0.01 0.01  0.02 0.05 0.02 0.1 1.01 1 0            331 A 0.01 0 0.01 0 0.01 0 0.02 0.03 0.04 0.005 0.08 1.01 1 0            332 A 0.01 0.01 0.02 0 0.02 0.01  0.03 0.05 0.03 0.1 1.01 1 0            333 A 0.02 0 0.02 0.01 0 0 0.01 0.02 0.04 0.06 0.08 1.01 1 0             334 A 0 0.02 0.02 0.02 0 0 0 0.02 0.04 0.03 0.08 1.005 2 0              335 A 0.01 0.02 0.03  0 0.01 0 0.01 0.04 0.03 0.09 1.01 2 0            336 A 0.01 0.01 0.02 0.01 0 0 0.01 0.02 0.04 0.03 0.08 1.01 2 0          337 A 0.01 0.01 0.02 0.02 0.01 0 0 0.03 0.05 0.02 0.1 1.005 2 0            338 A 0.005 0 0.005 0 0 0.005 0 0.005 0.01 0.02 0.02 1.001 2 0           339 A 0.01 0.01 0.02 0 0 0.01 0.01 0.02 0.04 0.03 0.08 1.01 0 1.5         340 A 0.03 0 0.03 0 0.02 0 0 0.02 0.05 0.02 0.1 1.035 2 0        341 A 0 0.02 0.02 0 0 0.01 0.01 0.02 0.04 0.03 0.08 1.01 0.2 0               342 A 0.01 0.01 0.02 0 0.01 0 0 0.01 0.03 0.03 0.06 1.01 3 0          343 A 0.01 0.01 0.02 0.02 0 0.01 0 0.03 0.05 0.03 0.1 1.01 0 0.2           344 A 0.02 0.01 0.03 0 0.03 0 0 0.03 0.06 0.02 0.13 1.005 0      3

    TABLE 12        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        *301 1300 1220 0.6 5.3 -12.5 6.5 -17.5 17.5 -18 5000 4750 210 200 13      14 0/72 980        *302 1300  820 0.7 2.5 -7.2 5 -7.5 7.6 -5 5110 4860 220 210 12 14 0/72        950        *303 1300 1450 0.6 3.2 -7.1 5.2 -7.6 8 -38 2900 2760 130 120 13 14      0/72 900        *304 1300  800 0.7 6.4 -13.5 7.6 -19.5 19.5 -7 4920 4670 230 220 12 14        0/72 100        *305 1280  710 2.2 3 -6.5 5 -7.3 7.5 -6 5030 4780 240 230 12 14 15/72        150        *306 1280 1220 0.6 2.2 -7.5 4 -8.4 8.6 -22 2850 2000 110  80 12 14      0/72 900        *307 1300 1340 0.7 2.5 -13.5 5 -31.5 31.5 -32 5110 4860 250 240 12 14      0/72 130        *308 Unmeasurable due to semiconductor formation        *309 1280 1460 0.7 3.3 -7.5 5.5 -18.5 18.5 -37 2940 2790 160 150 12 14      0 /72 110        *310 Unmeasurable due to semiconductor formation        *311 1300 1160 0.7 4 -7.6 5.6 -8 8.3 -20 3080 2930 170 160 10 11 0/72      100        *312 Unmeasurable due to insufficient sintering        *313 Unmeasurable due to insufficient sintering        *314 Unmeasurable due to insufficient sintering        *315 1300 1240 2.7 4 -7.4 5.8 -7.7 8.3 -22 3100 2950 160 150 10 12      0/72 130        *316 Unmeasurable due to insufficient sintering        *317 1300 1260 2.8 2.3 -8.3 5 -8.5 8.8 -22 3110 2960 170 160 11 12      0/72 100        *318 1300 1250 0.7 2.5 -8.1 7.2 -8.2 8.8 -21 5050 4800 240 230 13 14      0/72 880         319 1280 1380 0.7 5.5 -6.6 7 -7.1 8.1 -35 5000 4750 240 230 12 15      0/72 960         320 1280 1360 0.6 1.7 -7.3 7.5 -8 8.2 -35 4990 4740 230 220 12 14      0/72 940         321 1280 1130 0.6 2 -8.1 4 -8.5 8.6 -18 5170 4910 250 240 12 15 0/72      970         322 1300 1130 0.6 2.2 -8.3 4.5 -8.5 8.7 -18 5090 4840 230 220 12 14      0/72 900

    TABLE 13        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        323 1300  940 0.7 2.3 -8.2 5 -8.5 8.8 -11 5000 4750 210 200 12 15 0/72      9 30        324 1300 1320 0.6 2.1 -7.5 5.5 -8 8.2 -32 5120 4860 250 240 12 14 0/72        850        325 1300 1230 0.6 3.3 -7.5 6 -8.4 8.4 -23 5170 4910 250 240 12 14 0/72        870        326 1280 1280 0.6 3 -7.8 5.5 -8.3 8.5 -24 5080 4830 250 240 13 14 0/72        890        327 1280 1240 0.7 2.5 -8.1 5.1 -8.2 8.7 -19 5120 4860 250 240 12 15      0/72 900        328 1300  930 0.6 2.5 -8.3 6 -8.5 8.8 -11 5100 4850 250 240 13 14 0/72        960        329 1300 1250 0.6 2.3 -7.5 5.2 -7.9 8.5 -22 5010 4760 220 210 12 14      0/72 990        330 1300 1110 0.7 3 -7.7 5 -8 7.9 -17 5000 4750 220 210 12 14 0/72 900        331 1280 1260 0.6 2 -8 5.1 -8.2 8.1 -21 4980 4730 220 210 12 15 0/72      880        332 1280 1160 0.6 2.4 -7.4 5 -8.1 8 -21 5090 4840 250 240 12 14 0/72      820        333 1300 1220 0.7 3 -7.5 6.2 -8 8.1 -23 4920 4670 220 210 12 14 0/72      870        334 1300 1240 0.7 2.1 -7.7 6 -8.5 8.1 -21 5000 4750 200 190 12 14 0/72        900        335 1300 1250 0.6 1.9 -7.6 5.4 -8.3 8.5 -22 5010 4760 200 190 13 14      0/72 920        336 1280 1260 0.7 2.6 -7.8 5.8 -7.9 8.2 -22 5110 4860 250 240 13 14      0/72 880        337 1280 1150 0.6 2.3 -8.3 6.2 -8.5 8.8 -18 5100 4850 250 240 12 14      0/72 960        338 1280 1520 0.6 2 -7.5 6.1 -8.1 8.2 -40 5080 4830 250 240 12 14 0/72        900        339 1300 1260 0.6 2.4 -7.4 6.2 -7.5 8.3 -23 4990 4740 200 190 12 14      0/72 950        340 1300 1110 0.7 2 -7.6 6 -7.9 8.1 -17 5120 4860 250 240 12 14 0/72      940        341 1300 1270 0.6 2.6 -7.9 5.8 -8.5 8.5 -25 5100 4850 250 240 12 14      0/72 900        342 1300 1350 0.7 2.4 -7.8 7 -8.4 8.5 -33 5140 4880 250 240 12 14 0/72        920        343 1280 1130 0.7 2.2 -7.7 6.4 -8.3 8.5 -18 5190 4930 250 240 12 14      0/72 900        344 1300  980 0.7 2 -8.1 6 -8.5 8.8 -11 5100 4850 240 230 12 14 0/72      960

As is evident from TABLE 10 to TABLE 13, the monolithic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, alone with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, when the capacitor is used under a high electric field strength of 10 kV/mm, the insulation resistance represented by the product CR at 25° C. and 150° C. shows a high value of 4900 Ω•F or more and 200 Ω•F or more, respectively. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm under the DC voltage. The mean life span in the acceleration test at 150° C. and DC 25 kV/mm is as long as 800 hours along it being possible to conduct sintering at a relatively low sintering temperature of 1300° C.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +αM₂ O₃ +βR₂ O₃ +γBaZrO₃ +gMnO (wherein M₂ O₃ represents at least one of Sc₂ O₃ or Y₂ O₃ and R₂ O₃ represents at least one of Eu₂ O₃, Gd₂ O₃, Tb₂ O₃ and Dy₂ O₃, α, β, γ and g representing mole ratio, respectively), a M₂ O₃ content α of less than about 0.001 as shown in the sample No. 301 is not preferable because the temperature characteristic does not satisfy the B-level/X7R characteristics. On the other hand, the M₂ O₃ content α of more than about 0.05 as shown in the sample No. 302 is also not preferable because the specific dielectric constant is reduced to less than 900. Accordingly, the preferable range of the M₂ O₃ content α is 0.001≦α≦0.05.

It is not preferable that the R₂ O₃ content β of less than about 0.001 as in the sample No. 303 since the insulation resistance is so low that the product CR becomes small. It is also not preferable that the R₂ O₃ content β is more than about 0.05 as in the sample No. 304 because the temperature characteristic does not satisfy the B-level/X7R characteristics, reducing reliability. Accordingly, the preferable range of the R₂ O₃ content β is 0.001≦β≦0.05.

When the combined amount of M₂ O₃ and R₂ O₃ (α+β) is more than about 0.06 as in the sample No. 305, the dielectric loss is increased up to 2.0% while the mean life span is shortened, being not preferable since the number of rejects in the humidity resistance load test is increased. Accordingly, the combined amount of M₂ O₃ and R₂ O₃ (α+β) is preferably in the range of α+β≦0.06.

It is not preferable that, as seen in the sample No. 306, the BaZrO₃ content γ is zero since the insulation resistance becomes low while having a larger voltage dependency of the insulation resistance than in the system containing BaZrO₃. On the other hand, when BaZrO₃ content γ exceeds about 0.06 as in the sample No. 307, the temperature characteristic does not satisfy the B-level/X7R characteristics, being not preferable since the mean life span is shortened. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦γ≦0.06.

It is not preferable that, as seen in the sample No. 308, the MgO content g is about 0.001 since measurements are impossible due to semiconductor formation. On the other hand, it is not preferable that the MgO content g exceeds about 0.13 as seen in the sample No. 309 because the temperature characteristic X7R is not satisfied, the insulating resistance is low and the mean life span becomes short. Accordingly, the preferable range of the MgO content g is 0.001≦g≦0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 310 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample No. 311, the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage becomes low along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 as in the samples No. 312 and 313 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m<1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 314 and 316 because measurements are impossible due to insufficient sintering. It is not preferable that the amount of addition of the first or second side component exceeds about 3.0 parts by weight as seen in the samples No. 315 and 317, as the dielectric loss exceeds 1.0% and the insulation resistance and insulation breakdown voltage are lowered along with shortening the mean life span. Accordingly, the preferable content of either the first or the second components is 0.2 to 3.0 parts by weight.

The content of the alkali earth metal oxides contained in barium titanate as impurities are below about 0.02% by weight because when the content of the alkali earth metal oxides exceeds about 0.02% by weight as in the sample No. 318, the dielectric constant is decreased.

Example 5

A starting material of the composition of BaO₁.010 •TiO₂ +0.01Y₂ O₃ +0.02Dy₂ O₃ +0.01BaZrO₃ +0.06MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as the dielectric powder, in which oxides represented by LI₂ O--(Si, Ti)O₂ --MO with a mean particle size of 1 μm or less shown in TABLE 6 prepared by heating at 1200 to 1500° C. was added as a first side component. A monolithic ceramic capacitor was produced by the same method as in Example 1, except that the starting material as described above was used. The overall dimensions of the monolithic capacitor is the same as in Example 1. The electric characteristics were measured by the same method as in Example 1. The results are shown in TABLE 14. The samples No. 401 to 422 in TABLE 14 correspond to the samples No. 101 to 122 in TABLE 6, respectively, wherein, for example, the side component in the sample No. 101 in TABLE 6 is added to the sample No. 401 in TABLE 14.

    TABLE 14        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC rejection (h)        401 1280 1350 0.7 2.2 -8.4 4.8 -8.2 8.4 -33 4950 4700 220 210 13 15      0/72 920        402 1280 1380 0.6 2.1 -8 4.9 -8.1 8.3 -36 4970 4720 240 230 12 14 0/72        940        403 1280 1360 0.6 2.7 -7.9 5 -7.8 8.1 -33 4960 4710 230 220 13 15 0/72        930        404 1300 1310 0.6 2.1 -7.7 5.1 -7.9 8.3 -31 4990 4740 250 240 12 14      0/72 900        405 1300 1380 0.6 2.3 -7.9 4.7 -8.4 8.6 -36 5040 4790 230 220 12 14      0/72 870        406 1280 1380 0.6 2 -7.7 4.7 -8.5 8.7 -36 5010 4760 240 230 12 14 0/72        950        407 1280 1370 0.6 2 -7.5 5 -8.5 8.8 -35 5140 4880 250 240 12 14 0/72      930        408 1280 1380 0.6 2.8 -8 5 -8.2 8.5 -36 5030 4780 250 240 12 14 0/72      940        409 1280 1380 0.6 3 -7.4 4.9 -8.4 8.3 -36 4980 4730 240 230 12 14 0/72        900        410 1300 1350 0.6 2.4 -7.6 5.1 -8.5 8.7 -33 5000 4750 240 230 12 14      0/72 970        411 1300 1320 0.7 2.3 -7.5 5.4 -8.3 8.5 -32 4990 4740 230 220 12 14      0/72 920        412 1280 1360 0.6 2.7 -7.5 5.1 -8.2 8.3 -33 5050 4800 210 200 12 14      0/72 900        413 1350 Unmeasurable due to insufficient sintering        414 1350 Unmeasurable due to insufficient sintering        415 1350 1350 1.4 2.4 -7.7 5 -8.5 8.6 -33 5040 4790 240 230 11 13      32/72                                                                           416      1 350 Unmeasurable due to insufficient sintering        417 1350 Unmeasurable due to insufficient sintering        418 1300 1350 0.6 2.5 -7.5 5.1 -8.3 8.5 -33 5080 4830 230 220 12 14      0/72 880        419 1350 1370 1.3 2 -7.3 4.9 -8.2 8.5 -35 5100 4850 250 240 11 13      25/72        140                                                                420        1300 1350 0.7 2.4 -7.8 4.7 -8.5 8.7 -33 4960 4710 260 250 12 14 0/72      920        421 1350 1360 1.3 2.5 -8 4.3 -8.3 8.5 -33 5070 4820 250 240 11 13      33/72 110        422 1350 1330 1.2 2.3 -8.1 4.9 -8.2 8.5 -32 5070 4820 250 240 11 13      28/72 150

As is evident from TABLE 14, preferable results are obtained in the samples No. 401 to 412, 418 and 420, in which oxides in the samples No. 101 to 112, 118 and 120 in TABLE 6 with compositions within or on the boundary line of the area surrounded by the straight lines connecting the spots indicated by A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0), wherein x, y and z represent mole % and w is mole ratio, in the three component phase diagram of the Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO oxides shown in FIG. 4 are added, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

When the capacitor is used under a high electric field strength of 10 kV/mm, the insulation resistance represented by the product CR at 25° C. and 150° C. show a high value of 4900 Ω•F or more and 200 Ω•F or more, respectively. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm under the DC voltage. The mean life span in the acceleration test at 150° C. and DC 25 kV/mm is as long as 800 hours along with being possible to sinter at a relatively low sintering temperature of 1300° C.

On the contrary, when the oxide represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO is outside of the composition range described above as in the samples No. 113 to 117 and 119 in TABLE 6, sintering becomes insufficient or many samples are rejected in the humidity resistance load test even after sintering as seen in the samples No. 413 to 417 and 419. The samples with the composition falling on the line A-F and w=1.0 have a high sintering temperature and many rejects in the humidity resistance load test as seen in the samples No. 119 and 121 in TABLE 14. When the value of w is less than 0.30 as shown in the sample No. 122 in TABLE 6, the sintering temperature becomes high and there are many rejects in the humidity resistance load test as seen in the sample NO. 433 in TABLE 14.

Example 6

A starting material with a composition of BaO₁.010 •TiO₂ +0.01Y₂ O₃ +0.01Eu₂ O₃ +0.01Tb₂ O₃ +0.015BaZrO₃ +0.06MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder, in which the TABLE 8 oxide SiO₂ --TiO₂ --XO of mean particle size of 1 μm or less and prepared by heating at 1200 to 1500° C. was added as a second side component. A monolithic ceramic capacitor was produced by the same method and same overall dimensions as in Example 1, except that the starting material as described above was used. The electric characteristics were measured by the same method as in Example 1. The results are shown in TABLE 15. Samples No. 501 to 519 in TABLE 15 correspond to samples No. 201 to 219 in TABLE 8, respectively, wherein, for example, the sample No. 501 in TABLE 15 was obtained by adding the side component to the sample No. 201 in TABLE 8.

    TABLE 15        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        501 1300 1350 0.6 3.3 -8 6.2 -7.5 7.8 -34 4970 4720 210 200 12 14 0/72      9 00        502 1280 1370 0.6 3.2 -8.1 6.5 -7.7 7.9 -36 4980 4730 220 210 12 14      0/72 890        503 1280 1360 0.7 3.4 -8.2 6.7 -8 8.2 -34 5030 4780 220 210 12 14 0/72        930        504 1300 1330 0.6 4 -8 6.5 -8.1 8.2 -33 5020 4770 230 220 13 15 0/72      870        505 1300 1350 0.6 3.5 -8.1 6.8 -7.9 8.1 -34 4990 4740 230 220 12 14      0/72 850        506 1280 1320 0.6 3.4 -7.9 6.3 -7.7 8 -33 4980 4730 210 200 13 15 0/72        900        507 1280 1350 0.6 3.5 -8.1 6.4 -7.5 7.7 -34 4950 4700 230 220 12 14      0/72 880        508 1300 1360 0.6 3.3 -7.7 6.8 -7.8 8 -34 4950 4700 200 190 12 14 0/72        910        509 1300 1370 0.6 3.7 -8.1 6.5 -7.7 7.8 -36 4980 4730 230 220 12 14      0/72 880        510 1300 1360 0.6 3.5 -7.9 6.8 -7.5 7.7 -34 5000 4750 220 210 12 14      0/72 870        511 1280 1340 0.6 3.8 -8 7 -7.6 7.8 -33 5320 5050 310 300 12 14 0/72      900        512 1300 1330 0.6 3.4 -7.8 6.8 -7.8 8.2 -34 5330 5060 320 300 13 15      0/72 900        513 1350 1310 1.3 3.3 -7.8 6.8 -7.9 8.3 -33 5100 4850 220 210 11 13      42/72        120                                                                514      1 350 Unmeasurable due to insufficient sintering        515 1350 Unmeasurable due to insufficient sintering        516 1350 1300 1.2 3.5 -8 6.5 -7.5 7.7 -33 4950 4700 230 220 11 13      71/72        130                                                                517      1 350 Unmeasurable due to insufficient sintering        518 1350 Unmeasurable due to insufficient sintering        519 1350 Unmeasurable due to insufficient sintering

As is evident from the samples No. 501 to 512 in TABLE 15, preferable results are obtained in the samples in which the oxides of the samples No. 201 to 212 in TABLE 8 with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60), wherein x, y and z represent mole %, in the three component phase diagram of the oxides represented by SiO₂ --TiO₂ --XO shown in FIG. 5 are added, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of chance of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

When the capacitor is used under a high electric field strength of 10 kV/mm, the insulation resistance represented by the product CR at 25° C. and 150° C. show a high value of 4900 Ω•F or more and 200 Ω•F or more, respectively. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm under the DC voltage. The mean life span in the acceleration test at 150° C. and DC 25 kV/mm is as long as 800 hours along with being free from rejections in the humidity resistance load test and it is possible to sinter at a relatively low sintering temperature of 1300° C.

On the contrary, when the SiO₂ --TiO₂ --XO oxide is outside of the composition range described above, as in the samples No.213 to 219 in TABLE 8, the sintering becomes insufficient or many samples are rejected in the humidity resistance load test even after sintering as seen in the samples No. 513 to 519 in TABLE 15.

When Al₂ O₃ and/or ZrO₂ is allowed in the oxides represented by SiO₂ --TiO₂ --XO, as in the samples No.211 and 212 in TABLE 8, a monolithic capacitor having the insulation resistances of 5300 Ω•F or more and 300 Ω•F or more at 25° C. and 150° C., respectively, under an electric field strength of 10 kV/mm as the samples No. 511 and 512 in TABLE 15 can be obtained. However, when the amounts of addition of Al₂ O₃ and ZrO₂ exceed about 15 parts by weight and about 5 parts by weight, respectively, as in the samples No. 217 and 218 in TABLE 8, the sintering property is extremely deteriorated, as in the samples No. 217 and 218 in TABLE 8.

Example 7

After preparing and weighing TiCl₄ and Ba(NO₃)₂ having a variety of purity as starting materials, the compounds were precipitated as titanyl barium oxalate (BaTiO(C₂ O₄)•4H₂ O) by adding oxalic acid. This precipitate was decomposed by heating at a temperature of 1000° C. or more to synthesize four kinds of barium titanate listed in TABLE 1.

Oxides, carbonates or hydroxides of each component of the first side component were weighed so as to be a composition ratio (mole ratio) of 0.25Li₂ O-0.65(0.30TiO₂ •0.70SiO₂)-0.10Al₂ O₃ to obtain a powder by crushing and mixing.

Likewise, oxides, carbonates or hydroxides of each component of the second side component were weighed so as to be a composition ratio (mole ratio) of 0.66SiO₂ --0.17TiO₂ --0.15BaO-0.02MnO to obtain a powder by crushing and mixing.

Oxide powders of the first and second side components were placed in separate platinum crucibles and heated at 1500° C. After quenching and crushing the mixture, each oxide powder with a mean particle size of 1 μm or less was obtained.

In the next step, BaCO₃ for adjusting the mole ratio Ba/Ti (m) in barium titanate, and Sc₂ O₃, Y₂ O₃, BaZrO₃, MgO and MnO, each having a purity of 99% or more, were prepared. These raw material powders and the oxide first or second side component were weighted so as to form the compositions shown in TABLE 16 and TABLE 17. The amounts of addition of the first and second side components are indicated by parts by weight relative to 100 parts by weight of the essential component represented by (BaO)_(m) TiO₂ +αM₂ O₃ +γBaZrO₃ +hMgO+gMnO.

                                      TABLE 16                                     __________________________________________________________________________                                          Amount of addition                          (BaO).sub.m TiO.sub.2 + αM.sub.2 O.sub.3 + βBaZrO.sub.3 +                                                       γMgO + gMnO of the                                                       first Amount of addition of      Sample                                                                             Kind of                                                                            α                      components (parts                                                                       the second component             No. BaTiO.sub.3                                                                        Sc.sub.2 O.sub.3                                                                   Y.sub.2 O.sub.3                                                                    Total of α                                                                    β                                                                            γ                                                                           g   γ + g                                                                       m  by weight)                                                                              (parts by weight)                __________________________________________________________________________     *1001                                                                              1A  0   0.0008                                                                             0.0008                                                                              0.02                                                                              0.002                                                                             0.002                                                                              0.004                                                                             1.005                                                                             1        0                                  *1002 1A 0.01 0.06 0.07 0.03 0.07 0.05 0.12 1.005 1 0                          *1003 1A 0.01 0.02 0.03 0 0.03 0.02 0.05 1.01 1.5 0                            *1004 1A 0.02 0.01 0.03 0.08 0.02 0.04 0.06 1.01 1.5 0                         *1005 1A 0.01 0.01 0.02 0.02 0.001 0.034 0.035 1.01 1 0                        *1006 1A 0.01 0.02 0.03 0.02 0.125 0.005 0.13 1.01 1 0                         *1007 1A 0.02 0.02 0.04 0.02 0.079 0.001 0.08 1.01 1 0                         *1008 1A 0.01 0.02 0.03 0.02 0.005 0.125 0.13 1.01 1 0                         *1009 1A 0.01 0.02 0.03 0.03 0.08 0.06 0.14 1.01 1 0                           *1010 1A 0.02 0.01 0.03 0.03 0.02 0.03 0.05 0.99 1 0                           *1011 1A 0.01 0.01 0.02 0.04 0.03 0.02 0.05 1.00 1 0                           *1012 1A 0.02 0 0.02 0.04 0.02 0.01 0.03 1.038 1 0                             *1013 1A 0.01 0.01 0.02 0.02 0.03 0.01 0.04 1.05 0 1                           *1014 1A 0.01 0.01 0.02 0.02 0.01 0.02 0.03 1.01 0 0                           *1015 1A 0.02 0.01 0.03 0.02 0.03 0.02 0.05 1.01 5 0                           *1016 1A 0.01 0.01 0.02 0.02 0.01 0.03 0.04 1.01 0 0                           *1017 1A 0.005 0.025 0.03 0.02 0.03 0.02 0.05 1.01 0 4                         *1018 1D 0.01 0.02 0.03 0.03 0.03 0.03 0.06 1.01 2 0                            1019 1A 0 0.001 0.001 0.02 0.002 0.0015 0.003 1.015 1 0                        1020 1B 0.02 0 0.02 0.03 0.02 0.01 0.03 1.02 1 0                               1021 1C 0.005 0.05 0.055 0.03 0.12 0.002 0.122 1.03 1 0                        1022 1A 0 0.04 0.04 0.03 0.03 0.04 0.07 1.02 1 0                               1023 1A 0 0.06 0.06 0.03 0.01 0.12 0.13 1.01 0 1                            __________________________________________________________________________

                                      TABLE 17                                     __________________________________________________________________________                                        Amount of                                                                            Amount of                                addition of addition of                                                       (BaO).sub.m TiO.sub.2 + αM.sub.2 O.sub.3 + βBaZrO.sub.3 +                                                  γMgO + gMnO the first the                                                second                                Kind of   α                                                                               Total             side  side                                  Sample No.                                                                           BaTiO.sub.3                                                                        Sc.sub.2 O.sub.3                                                                   Y.sub.2 O.sub.3                                                                   of α                                                                        β                                                                            γ                                                                           g  γ + g                                                                       m  component                                                                            component                             __________________________________________________________________________     1024  1A  0   0.01                                                                              0.01                                                                              0.005                                                                             0.01                                                                              0.02                                                                              0.03                                                                              1.01                                                                              1     0                                       1025 1A 0 0.02 0.02 0.04 0.01 0.03 0.04 1.01 1 0                               1026 1A 0 0.03 0.03 0.06 0.03 0.02 0.05 1.01 1 0                               1027 1A 0.01 0.04 0.05 0.03 0.06 0.05 0.11 1.01 2 0                            1028 1A 0 0.005 0.005 0.02 0.005 0.006 0.011 1.001 2 0                         1029 1A 0 0.04 0.04 0.03 0.05 0.02 0.07 1.01 0 2                               1030 1A 0 0.02 0.02 0.03 0.02 0.03 0.05 1.035 2 0                              1031 1A 0 0.02 0.02 0.03 0.03 0.01 0.04 1.015 0.2 0                            1032 1A 0 0.02 0.02 0.03 0.02 0.03 0.05 1.01 3 0                               1033 1A 0 0.02 0.02 0.03 0.02 0.015 0.035 1.01 0 0.2                           1034 1A 0 0.02 0.02 0.03 0.03 0.01 0.04 1.01 0 3                             __________________________________________________________________________

An organic solvent such as polyvinyl butyral binder and ethanol was added to the weighed compounds and the mixture was mixed in a ball mill in an wet state to prepare a ceramic slurry. This ceramic slurry was formed into a sheet by a doctor blade method to obtain a rectangular shaped green sheet with a thickness of 35 μm, followed by printing an electroconductive paste of Ni on the ceramic green sheet to form an electroconductive paste layer for forming inner electrodes.

Then, a plurality of the ceramic green sheets on which the electroconductive layer is formed were laminated so that the sides where the electroconductive paste projected are alternately placed, thus obtaining a monolithic body. This monolithic body was heated at 350° C. in a N₂ atmosphere and, after allowing the binder to decompose, the monolithic body was fired at the temperatures shown in TABLE 18 and TABLE 19 in a reducing atmosphere comprising H₂ --N₂ --H₂ O gases under an oxygen partial pressure of 10⁻⁹ to 10⁻¹² MPa for two hours, thereby obtaining a ceramic sintered body.

Both side faces of the ceramic sintered body were coated with a silver paste containing B₂ O₃ --Li₂ O--SiO₂ --BaO glass frit and fired at a temperature of 600° C. in a N₂ atmosphere, thereby obtaining outer electrodes electrically connected to the inner electrodes.

The overall dimensions of the monolithic ceramic capacitor thus obtained were 5.0 mm in width, 5.7 mm in length and 2.4 mm in thickness while the thickness of each dielectric ceramic layer was 30 μm. Total number of the effective dielectric ceramic layers were 57, the area of the confronting electrode per layer being 8.2×10⁻⁶ m².

Electric characteristics of these monolithic ceramic capacitors were measured. The electrostatic capacitance (C) and dielectric loss (tan δ) were measured using an automatic bridge type measuring instrument at 1 kHz, 1 Vrms and 25° C. and the dielectric constant (ε) was calculated from the electrostatic capacitance. Next, the insulation resistance was measured using an insulation resistance tester at 25° C. and 150° C. by impressing direct current voltages of 315 V (or 10 kV/mm) and 945 V (or 30 kV/mm) for 2 minutes, obtaining a product of the electrostatic capacitance and insulation resistance, or a product CR.

The rate of change of the electrostatic capacitance against temperature changes was also measured. The rate of change at -25° C. and 85° C. by taking the electrostatic capacitance at 20° C. as a standard (ΔC/C₂₀), the rate of change at -55° C. and 125° C. by taking the electrostatic capacitance at 20° C. as a standard (ΔC/C₂₅) and the maximum value of the rate of change (|ΔC|_(max)) as an absolute value were measured as the electrostatic capacitances against temperature changes.

The DC vias characteristic was also evaluated. First, the electrostatic capacitance when an AC voltage of 1 kHz and 1 Vrms was impressed was measured. Then, the electrostatic capacitance when a DC voltage of 150 V and an AC voltage of 1 kHz and 1 Vrms were simultaneously impressed was measured, thereby the rate of reduction of the electrostatic capacitance (ΔC/C) due to loading the DC voltage was calculated.

In the high temperature load test, a direct current voltage of 750 V (or 25 kV/mm) was impressed at 150° C. on 36 pieces of each sample to measure the time dependent changes of the insulation resistance. The time when the insulation resistance of each sample was reduced below 10⁶ Ω was defined to be a life span time and mean life span time was evaluated.

In the humidity resistance test, the number of the test pieces having an insulation resistance of 10⁶ Ω or less among the 72 test pieces were counted after impressing a DC voltage of 315 V under an atmospheric pressure of 2 atm (relative humidity 100%) at 120° C. for 250 hours.

Insulation breakdown voltages under AC and DC voltages were measured by impressing AC and DC voltages at a voltage increase rate of 100 V/sec.

The results described above are listed in TABLE 18 and TABLE 19.

    TABLE 18        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        *1001 1300 1140 0.8 5.5 -12.5 4.6 -17.2 20 -17 5130 4870 210 200 12 14      0 /72 890        *1002 1300 850 0.7 2.1 -7.2 4.4 -6.5 8 -12 8490 8070 190 180 12 14      0/72 850        *1003 1280 1020 0.6 2 -8 4.2 -8.2 9.1 -15 3140 2200 150 110 12 14 0/72        840        *1004 1300 1360 0.7 2.4 -14.7 5.1 -29.5 35.4 -26 5170 4910 230 220 12      14 0/72 150        *1005 1280 1220 0.7 3.2 -14.2 4.1 -17.9 23 -21 3070 2920 130 120 13 14        0/72 830        *1006 1360 1400 2.7 2.5 -8.3 4.3 -8.6 9 -35 5140 4880 220 210 12 14      61/72        180      *1007 Unmeasurable due to semiconductor formation        *1008 1280 1340 0.8 3.5 -8.9 4.8 -18.6 25.1 -28 3140 2980 140 130 12      14 0/72 190        *1009 1280 880 2.6 3.5 -9.2 3.8 -9.1 9.9 -12 5010 4760 240 230 12 14      15/72        130      *1010 Unmeasurable due to semiconductor formation        *1011 1300 1280 0.7 3.9 -9 4.7 -9.3 10.2 -25 3300 3140 160 150 10 12      0/72 110        *1012 Unmeasurable due to insufficient sintering        *1013 Unmeasurable due to insufficient sintering        *1014 Unmeasurable due to insufficient sintering        *1015 1300 1280 2.3 4 -8.9 4.2 -9.4 10.9 -25 3310 3150 160 150 11 11      0/72 150        *1016 Unmeasurable due to insufficient sintering        *1017 1300 1260 2.5 2.8 -8.4 3.1 -7.6 8.4 -23 3150 2990 180 170 10 11      0/72 170        *1018 1300 1030 0.7 2.5 -7.9 5.6 -9.4 9.2 -15 5120 4860 260 250 12 14      0/72 870         1019 1280 1580 0.7 2.5 -7.2 3.8 -8.5 8.8 -45 5070 4820 260 250 12 15      0/72 950         1020 1280 1520 0.6 2.6 -7 4 -8 8.6 -45 5050 4800 240 230 12 14 0/72      960         1021 1280 1080 0.6 3 -8 4.1 -8.2 9 -15 5290 5030 280 270 12 15 0/72      820         1022 1300 1320 0.6 2.5 -8.3 3.8 -8.6 8.8 -26 5160 4900 250 240 12 14      0/72 830         1023 1300 1050 0.7 2.4 -8.1 4.2 -8.4 8.9 -15 5230 4970 220 210 13 15      0/72 840

    TABLE 19        - DC vias Product CR (Ω ·       F)  Humidity                      Ratio of Temperature Dependent      Capacitance characteristic 315 V 945 V 315 V 945 V Insulation breakdown      Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        1024 1300 1570 0.6 2.9 -7.9 4.1 -8.2 8.8 -45 5180 4920 230 220 12 14      0/72 890        1025 1300 1480 0.7 3.1 -7.1 4.3 -7.9 8.5 -40 5300 5040 270 260 12 15      0/72 900        1026 1280 1420 0.6 3.2 -8.1 3.8 -8.3 9 -35 5240 4980 280 270 13 14      0/72 830        1027 1280 1230 0.7 2.4 -7.5 3.9 -8.1 8.6 -22 5260 5000 220 210 12 14      0/72 840        1028 1300 1590 0.6 2.8 -7.6 4.2 -7.9 8.4 -45 5280 5020 200 190 12 14      0/72 860        1029 1300 1330 0.6 2.7 -7.2 4.3 -8.2 8.6 -26 5040 4790 210 200 12 14      0/72 950        1030 1300 1540 0.6 2.6 -7.9 4.5 -8.1 8.8 -42 5230 4970 240 230 13 14      0/72 900        1031 1280 1560 0.6 2.5 -8 4.l -8.5 8.9 -42 5080 7830 270 260 12 15      0/72 870        1032 1280 1550 0.6 2 -8.1 3.9 -8.2 8.7 -42 5190 4930 210 200 12 14      0/72 890        1033 1300 1540 0.7 2.4 -7.8 3.9 -8.5 9.1 -42 5140 4880 210 200 12 14      0/72 860        1034 1300 1520 0.6 2.5 -7.6 4.2 -8.4 9.2 -43 5080 4830 230 220 12 14      0/72 840

It is evident from Table 16 to TABLE 19 that the monolithic ceramic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of less than 1.0%, wherein the rate of change against temperature changes satisfies both the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +αM₂ O₃ +γBaZrO₃ +gMnO+hMgO (wherein M₂ O₃ represents at least one of either Sc₂ O₃ or Y₂ O₃, α, γ, g, and h represent mole ratio, respectively), a M₂ O₃ content α of less than about 0.001 as shown in the sample No. 1001 is not preferable because the temperature characteristic does not satisfy the B-level/X7R characteristics. On the other hand, the M₂ O₃ content α of more than about 0.06 as shown in the sample No. 1002 is also not preferable because the specific dielectric constant is reduced to less than 1000. Accordingly, the preferable range of the M₂ O₃ content α is 0.001≦α≦0.06.

It is not preferable that the BaZrO₃ content γ be zero as in the sample No. 1003 is not preferable since the insulation resistance is low and the voltage dependency of the insulating resistance is larger than that of the composition system containing BaZrO₃. It is also not preferable that the BaZrO₃ content γ is more than about 0.06 as in the sample No. 1004 because the temperature characteristic does not satisfy the B-level/X7R characteristics, along with shortening the mean life span. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦γ≦0.06.

It is not preferable that, as seen in the sample No. 1005, the MgO content h is about 0.001 since the insulation resistance becomes low and the temperature characteristic does not satisfy the B-level/X7R characteristics. It is not preferable, on the other hand, that the MgO content h exceed about 0.12 as in the sample No. 1006, because the sintering temperature becomes high, the dielectric loss exceeds 2.0%, the number of rejections in the humidity resistance load test is extremely increased along with shortening the mean life span. Accordingly, the preferable range of the MgO content h is in the range of 0.001<h≦0.12.

It is not preferable that, as seen in the sample No. 1007, the MnO content g is about 0.001 Since measurement becomes impossible due to formation of semiconductors. It is not preferable, on the other hand, that the MnO content g exceed about 0.12 as seen in the sample No. 1008 because the temperature characteristic X7R is not satisfied and the insulation resistance is lowered and the mean life span becomes short. Accordingly, the preferable range of the MnO content g is in the range of 0.001<g≦0.12.

It is not preferable that, as in the sample No. 1009, the combined amount of g+h of the MgO content h and MnO content g exceed about 0.13 because the dielectric loss is increased to 2.0% and the mean life span is shortened and the rejection number in the humidity resistance load test increases. Accordingly, the combined amount of g+h of the MgO content h and MnO content g is preferably in the range of g+h≦0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 1010 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample

No. 1011, the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage are lowered along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 as in the samples No. 1012 and 1013 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m≦1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 1014 and 1016 because measurements are impossible due to insufficient sintering. It is not preferable that the amount of addition of the first or second side component exceed about 3.0 parts by weight as seen in the samples No. 1015 and 1017, because the dielectric loss exceeds 1.0% and the insulation resistance and Insulation breakdown voltage are lowered along with shortening the mean life span. Accordingly, the preferable content of either the first or the second components is 0.2 to 3.0 parts by weight.

The contents of the alkali earth metal oxides contained in barium titanate as impurities is below about 0.02% by weight because when the contents of the alkali earth metal oxides exceed about 0.02% by weight as in the sample No. 1018, the dielectric constant is decreased.

Example 8

A material with a composition of BaO₁.010 •TiO₂ +0.03Y₂ O₃ +0.02BaZrO₃ +0.05MgO+0.01 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 7, except that an oxide represented by Li₂ O--(Si, Ti)O₂ --MO shown in Table 20, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the first side component. The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 7.

The electric characteristics were then measured by the same method as in Example 7. The results are shown in TABLE 21.

                  TABLE 20                                                         ______________________________________                                         The first side component                                                                  Amount of                                                              addition                                                                      Sample (parts by Composition (mol %, except w)                               No.    weight)  Li.sub.2 O                                                                             (Si.sub.w Ti.sub.l-w)O.sub.2                                                           w    Al.sub.2 O.sub.3                                                                     ZrO.sub.2                           ______________________________________                                         1101   1        20      80      0.3  0     0                                     1102 1 10 80 0.6 5 5                                                           1103 0.8 10 70 0.5 20 0                                                        1104 0.8 35 45 1 10 10                                                         1105 1.5 45 45 0.5 10 0                                                        1106 1.5 45 55 0.3 0 0                                                         1107 1 20 70 0.6 5 5                                                           1108 1 20 70 0.4 10 0                                                          1109 1.2 30 60 0.7 5 5                                                         1110 1.2 30 60 0.8 10 0                                                        1111 2 40 50 0.6 5 5                                                           1112 2 40 50 0.9 0 10                                                          1113 1.5 10 85 0.4 5 0                                                         1114 2 5 75 0.6 10 10                                                          1115 1.2 20 55 0.5 25 0                                                        1116 1 45 40 0.8 0 15                                                          1117 0.8 50 45 0.7 5 0                                                         1118 1.2 25 75 0.9 0 0                                                         1119 1.5 25 75 1 0 0                                                           1120 1 35 65 0.9 0 0                                                           1121 1.5 35 65 1 0 0                                                           1122 1.2 20 70 0.2 0 10                                                      ______________________________________                                    

    TABLE 21        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        1001 1280 1430 0.8 2.5 -8.2 3.3 -8.4 9.4 -36 5120 4860 220 210 13 14      0/72 840        1102 1280 1450 0.6 2.3 -8.4 3.8 -8.6 9.5 -37 5080 4830 230 220 13 14      0/72 890        1103 1280 1490 0.6 2.4 -7.9 4.2 -8.2 9.9 -39 5160 4900 220 210 12 14      0/72 850        1104 1300 1470 0.7 2.1 -7.8 4.6 -8.1 8.9 -39 5200 4940 210 200 12 15      0/72 830        1105 1300 1430 0.6 2 -7.8 3.5 -8.3 9.4 -36 5180 4920 230 220 13 14      0/72 900        1106 1280 1450 0.7 2.6 -8.2 3.7 -8.6 9.2 -37 5090 4840 210 200 12 14      0/72 870        1107 1280 1430 0.8 2.8 -8.6 3.8 -8.9 9.3 -36 5070 4820 220 210 13 14      0/72 830        1108 1280 1440 0.6 2.9 -8.4 4.1 -8.7 8.9 -36 5030 4780 220 210 12 14      0/72 890        1109 1280 1480 0.7 2.4 -7.6 4.2 -8.2 8.8 -39 5220 4960 210 200 12 14      0/72 910        1110 1300 1470 0.6 2.6 -7.4 3.8 -8.3 8.8 -39 5080 4830 230 220 13 14      0/72 870        1111 1300 1420 0.8 2.4 -8 3.9 -8.1 9 -36 5100 4850 200 190 12 14 0/72      850        1112 1280 1410 0.6 2.2 -8.4 3.9 -8.6 9.1 -35 5180 4920 210 200 12 14      0/72 840        1113 1350 Unmeasurable due to insufficient sintering        1114 1350        1115 1350 1460 1.5 2.8 -7.8 4.2 -8.2 8.9 -37 4820 4580 190 180 11 13      32/72        180      1116 1350 Unmeasurable due to insufficient sintering        1117 1350 Unmeasurable due to insufficient sintering        1118 1300 1420 0.8 2.9 -7.9 4.8 -8.3 9.1 -36 5160 4900 210 200 12 14      0/72 860        1119 1350 1430 1.4 2.7 -8.2 4.2 -8.4 9.2 -36 4890 4650 190 180 11 13      16/72        150      1120 1300 1450 0.7 2.5 -8 4 -8.2 9.4 -37 5130 4870 210 200 12 14 0/72      840        1121 1350 1460 1.4 2.2 -8.1 3.8 -8.6 9.1 -38 4950 4700 190 180 11 13      36/72        140      1122 1350 1450 1.3 2.3 -8.3 3.8 -8.7 9.1 -38 4870 4630 190 180 11 13      25/72        190

As is evident from TABLE 20 and TABLE 21, preferable results are obtained in the samples No. 1101 to 1112, 1118 and 1120, in which oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0), (wherein x, y and z represent mole % and w represents mole ratio, which is in the range of 0.3≦w<1.0 in the composition on the line A-F) of the three component phase diagram of the oxides represented by Li,O--(Si_(w), Ti_(1-w))O₂ --MO shown in FIG. 4 are added, wherein the samples have a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show values as high as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more and a relatively low firing temperature of 1300° C. or less could be used.

On the contrary, when the Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO oxide is outside of the composition range described above as shown in the samples No. 1113 to 1117, and 1119, the sintering becomes insufficient or many samples are rejected in the humidity resistance load test even after sintering. The samples with the composition falling on the line A-F and w=1.0 as in the samples No. 1119 and 1121 have high sintering temperature along with causing many rejects in the humidity resistance load test. When the value of w is less than about 0.30 as shown in the sample No. 1122, the sintering temperature becomes high along with causing many rejects in the humidity resistance load test.

Example 9

A material with a composition of BaO₁.010 @TiO₂ +0.03Sc₂ O₃ +0.01 5BaZrO₃ +0.05MgO+0.01 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 7, except that an oxide Li₂ O--TiO₂ --XO shown in Table 22, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the second side component. The amounts of addition of Al₂ O₃ and ZrO₂ correspond to parts by weight relative to 100 parts by weight of (xSiO₂ --yTiO₂ --zXO). The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 7.

The electric characteristics were then measured by the same method as in Example 7. The results are shown in TABLE 23.

                                      TABLE 22                                     __________________________________________________________________________     The second side component                                                               Essential component (mol %)                                           Sample                                                                             Amount of  XO                   Added component (Parts by weight)          No. addition                                                                            SiO.sub.2                                                                         TiO.sub.2                                                                         BaO                                                                               CaO                                                                               SrO                                                                               MgO                                                                               ZnO                                                                               MnO                                                                               Total                                                                             Al.sub.2 O.sub.3                                                                        ZrO.sub.2                         __________________________________________________________________________     1201                                                                               1    85 1  1  0  0  0  4  9  14 0        0                                   1202 1 35 51 0 10 0 0 0 4 14 0 0                                               1203 1 30 20 0 30 0 15 4 1 50 0 0                                              1204 1 39 1 20 20 2 0 13 5 60 0 0                                              1205 1 70 10 5 5 0 0 10 0 20 0 0                                               1206 1 45 10 0 0 0 0 15 30 45 0 0                                              1207 1 50 20 10 10 3 7 0 0 30 0 0                                              1208 1 50 30 0 16 0 0 0 4 20 0 0                                               1209 1 35 30 25 10 0 0 0 0 35 0 0                                              1210 1 40 40 10 0 0 0 5 5 20 0 0                                               1211 1 45 22 3 30 0 0 0 0 33 15 0                                              1212 1 45 22 3 30 0 0 0 0 33 10 5                                              1213 1 65 25 5 5 0 0 0 0 10 0 0                                                1214 1 25 40 15 0 10 0 5 5 35 0 0                                              1215 1 30 10 30 25 0 0 5 0 60 0 0                                              1216 1 50 0 35 15 0 0 0 0 50 0 0                                               1217 1 45 22 30 0 0 3 0 0 33 25 0                                              1218 1 45 22 30 0 3 0 0 0 33 0 15                                              1219 1 30 60 10 0 0 0 0 0 10 0 0                                             __________________________________________________________________________

    TABLE 23        - DC vias Product CR (Ω · F) Insulation Humidity                Ratio of Temperature Dependent Capacitance characteristic 315      V 945 V 315 V 945 V breakdown Resistance        Baking  Dielectric Change (%) (%) Impressed Impressed Impressed      Impressed voltage Load Test: Mean        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Number of      Life Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        1201 1300 1520 1.3 2.4 -7.2 2.5 -7.5 8.1 -41 5010 4760 200 190 12 14      0/72 820        1202 1300 1530 1.4 2.3 -7.5 2.4 -7.8 8.2 -41 5000 4750 210 200 12 14      0/72 810        1203 1300 1550 1.3 2.2 -7.8 2.3 -7.9 8 -42 5020 4770 200 190 13 14      0/72 800        1204 1300 1540 1.3 2.3 -7.7 2.4 -7.8 8.3 -41 5010 4760 200 190 12 15      0/72 860        1205 1300 1520 1.3 2.4 -7.5 2.2 -7.6 8.1 -41 5030 4780 200 190 12 14      0/72 830        1206 1300 1530 1.3 2.2 -7.4 2 -7.8 8.1 -41 5010 4760 200 190 13 15      0/72 890        1207 1300 1560 1.3 2.3 -7.6 2.1 -7.9 8.2 -42 5000 4750 210 200 12 14      0/72 870        1208 1300 1520 1.3 2.4 -7.5 2.3 -8 8.2 -41 5010 4760 200 190 12 14      0/72 850        1209 1300 1530 1.3 2.2 -7.1 2.4 -7.8 8.3 -41 5020 4770 200 190 13 14      0/72 820        1210 1300 1510 1.4 2.3 -7.5 2.4 -7.9 8.1 -41 5030 4780 200 190 12 14      0/72 810        1211 1300 1530 1.3 2.5 -7.2 2.5 -7.8 8 -41 5420 5150 320 300 12 14      0/72 860        1212 1300 1540 1.3 2.1 -7.1 2.2 -7.6 8.1 -41 5410 5140 300 290 12 14      0/72 840        1213 1350 1550 1.5 2 -7 2.3 -7.6 8.2 -42 4830 4590 200 190 11 13 52/72         160        1214 1350 Unmeasurable due to insufficient sintering        1215 1350 Unmeasurable due to insufficient sintering        1216 1350 1560 1.6 2.3 -7.2 2.4 -7.8 8.2 -42 4790 4550 200 190 1 13      72/72        180      1217 1350 Unmeasurable due to insufficient sintering        1218 1350 Unmeasurable due to insufficient sintering        1219 1350 Unmeasurable due to insufficient sintering

As is evident from TABLE 22 and TABLE 23, preferable results are obtained in the samples No. 1201 to 1212 in which oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60), (wherein x, y and z represent mole %) of the three component phase diagram of the oxides represented by SiO₂ --TiO₂ --XO shown in FIG. 5 are added, wherein the samples have a capacitance decreasing ratio of as small as -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more. Enabled was a relatively low firing temperature of 1300° C. or less.

When the composition of the oxide represented by SiO₂ --TiO₂ --XO is out of the composition range described above, on the other hand, sintering becomes insufficient as seen in the samples No.1213 to 1219 or many rejects occur in the humidity resistance load test even after the sintering.

When Al₂ O₃ and/or ZrO2 is in the oxide represented by SiO₂ --TiO₂ --XO as in the samples No. 1211 and 1212, a monolithic capacitor having the insulation resistances of 5400 Ω•F or more and 300 Ω•F or more at 25° C. and 150° C., respectively, under an electric field strength of 10 kV/mm can be obtained. However, when the amounts of addition of Al₂ O₃ and ZrO₂ exceed about 15 parts by weight and about 5 parts by weight, respectively, the sintering property is extremely deteriorated as in the samples No. 1217 and 1218.

Example 10

The four kinds of barium titanate (BaTiO₃) in TABLE 1, an oxide powder as a first side component and an oxide powder as a second side component were obtained by the same method as in Example 1.

Then, BaCO₃ for adjusting the Ba/Ti mole ratio m in barium titanate, and Sc₂ O₃, Y₂ O₃, BaZrO₃ and MnO with purity of 99% or more were prepared. These raw material powder and powder of the first or second side component were weighed so as to be the composition shown in TABLE 24 and TABLE 25. The amount of addition of the first or second side component corresponds to the amount relative to 100 parts of the essential component of ((BaO)_(m) TiO₂ +αM₂ O₃ +βBaZrO₃ +(MnO). A monolithic ceramic capacitor was produced using this weighed compounds by the same method as in Example 7. The overall dimensions of the monolithic ceramic capacitor produced are the same as in Example 7.

                                      TABLE 24                                     __________________________________________________________________________                                     Amount of                                                                              Amount of                                 addition of the addition of the                                               (BaO).sub.m TiO.sub.2 + αM.sub.2 O.sub.3 + βBaZrO.sub.3 +                                                 γMnO first side second side      Kind of   α Total         component (parts                                                                       component (parts                       Sample No.                                                                           BaTiO.sub.3                                                                        Sc.sub.2 O.sub.3                                                                   Y.sub.2 O.sub.3                                                                    of α                                                                         β                                                                            γ                                                                            m  by weight)                                                                             by weight)                             __________________________________________________________________________     *1301 1A  0   0.0008                                                                             0.0008                                                                             0.01                                                                              0.0015                                                                             1.005                                                                             1       0                                        *1302 1A 0.03 0.045 0.075 0.02 0.15 1.01 1 0                                   *1303 1A 0.01 0.01 0.02 0 0.042 1.01 1.5 0                                     *1304 1A 0.02 0.01 0.03 0.07 0.06 1.01 1.5 0                                   *1305 1A 0 0.02 0.02 0.02 0.001 1.01 1 0                                       *1306 1A 0.02 0 0.02 0.03 0.14 1.01 1 0                                        *1307 1A 0 0.03 0.03 0.03 0.06 0.99 1 0                                        *1308 1A 0.005 0.015 0.02 0.04 0.041 1 1 0                                     *1309 1A 0 0.02 0.02 0.03 0.04 1.038 1 0                                       *1310 1A 0 0.03 0.03 0.02 0.06 1.045 0 1                                       *1311 1A 0 0.02 0.02 0.02 0.04 1.01 0 0                                        *1312 1A 0 0.02 0.03 0.02 0.06 1.01 5 0                                        *1313 1A 0.01 0.01 0.03 0.02 0.063 1.02 0 0                                    *1314 1A 0.02 0.02 0.02 0.03 0.04 1.01 0 4                                     *1315 ID 0 0.03 0.03 0.03 0.06 1.02 1.5 0                                    __________________________________________________________________________

                                      TABLE 25                                     __________________________________________________________________________                                  Amount of                                                                              Amount of                                    addition of the addition of the                                               (BaO).sub.m TiO.sub.2 + αM.sub.2 O.sub.3 + βBaZrO.sub.3 +                                              γMnO first side second side         Kind of   α                                                                               Total       component (parts                                                                       component (parts                          Sample No.                                                                           BaTiO.sub.3                                                                        Sc.sub.2 O.sub.3                                                                   Y.sub.2 O.sub.3                                                                   of α                                                                        β                                                                            γ                                                                           m  by weight)                                                                             by weight)                                __________________________________________________________________________     1316  A   0   0.001                                                                             0.001                                                                             0.02                                                                              0.002                                                                             1.01                                                                              1       0                                           1317 B 0 0.02 0.02 0.03 0.04 1.02 1 0                                          1318 C 0.01 0 0.01 0.03 0.13 1.03 1 0                                          1319 A 0.01 0.04 0.05 0.04 0.1 1.02 1 0                                        1320 A 0.02 0.04 0.06 0.03 0.12 1.01 0                                         1321 A 0 0.01 0.01 0.005 0.02 1.01 1 0                                         1322 A 0.01 0.01 0.02 0.04 0.04 1.01 2 0                                       1323 A 0 0.03 0.03 0.06 0.06 1.01 1 0                                          1324 A 0.02 0.02 0.04 0.03 0.078 1.01 2 0                                      1325 A 0 0.01 0.01 0.02 0.02 1.001 2 0                                         1326 A 0 0.005 0.005 0.04 0.01 1.02 0 2                                        1327 A 0.01 0.01 0.02 0.03 0.04 1.035 2 0                                      1328 A 0.02 0 0.02 0.03 0.04 1.025 0.2 0                                       1329 A 0.01 0.01 0.02 0.03 0.04 1.01 3 0                                       1330 A 0 0.02 0.02 0.03 0.041 1.01 0 0.2                                       1331 A 0 0.02 0.02 0.03 0.04 1.01 0 3                                        __________________________________________________________________________

The electric characteristics were measured by the same method as in Example 7. The results are shown in TABLE 26 and TABLE 27.

    TABLE 26        - DC vias Product CR (Ω ·       F)                                Ratio of Temperature Dependent      Capacitance Change characteristic 315 V 945 V 315 V 945 V Insulation      Humidity        Baking  Dielectric (%) (%) Impressed Impressed Impressed Impressed      breakdown voltage Resistance Load Mean Life        Sample Temp. Dielectric Loss ΔC/C.sub.20 ΔC/C.sub.25      Maximum ΔC/C Voltage Voltage Voltage Voltage (kV/mm) Test: Number      of Span        No. (° C.) Constant tan δ (%) -25° C. 85°      C. -55° C. 125° C. value 5 kV/mm 25° C. 150°        C. AC DC reject (h)        *1301 1300 1570 0.7 5 -12 4.2 -16.7 16.7 -42 5100 4850 200 190 12 14      0/72 900        *1302 1300 820 0.7 2.2 -6.7 4 -6 6.7 -9 5500 5230 180 170 12 14 0/72      910        *1303 1300 1450 0.7 2.1 -7.5 4 -7.7 8.2 -36 3020 2110 100  70 12 14      0/72 890        *1304 1300 1350 0.7 2.3 -14.2 5.3 -28 28 -27 5100 4850 200 190 12 14      0/72 120        *1305 Unmeasurable due to semiconductor formation        *1306 1280 1420 0.8 3.5 -8.4 4.5 -18.1 18 -36 3120 2960 140 130 12 14      0/72 140        *1307 Unmeasurable due to insufficient sintering        *1308 1300 1410 0.7 3.5 -8.5 4.3 -8.8 9.1 -35 3100 2950 130 120 10 12      0/72 100        *1309 Unmeasurable due to insufficient sintering        *1310 Unmeasurable due to insufficient sintering        *1311 Unmeasurable due to insufficient sintering        *1312 1300 1330 2.3 3.6 -8.4 4.1 -8.9 9.2 -27 3330 3160 140 130 11 11      0/72 130        *1313 Unmeasurable due to insufficient sintering        *1314 1300 1450 2.5 2.7 -7.9 3.2 -7.1 7.9 -369 3150 2990 160 150 10 11      0 /72 160        *1315 1300 1310 0.7 2.6 -7.4 5.5 -8.9 9.2 -25 5060 4810 230 220 12 14      0/72 920

                                      TABLE 27                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       1316 1280 1590 0.7 2.5 -.7 3  -8 8.4 -40                                       1317 1280 1450 0.6 2.7 -.5 3.8 -7.5 8 -36                                      1318 1280 1570 0.7 3 -7.5 3.5 -7.7 8.2 -39                                     1319 1300 1110 0.6 2.6 -7.8 3.7 -8.5 8.8 -15                                   1320 1300  940 0.6 2.5 -7.6 4.1 -7.8 8.1 -12                                   1321 1300 1530 0.6 2.7 -7.4 4 -7.6 8 -40                                       1322 1300 1460 0.7 3 -.6 4.2 -7.4 7.9 -37                                      1323 1300 1340 0.6 3.1 -7.6 4 -7.8 8.2 -26                                     1324 1280 1230 0.7 2.5 -7 3.7 -7.6 7.9 -22                                     1325 1300 1560 0.6 2.7 -7.1 4 -7.3 7.7 -40                                     1326 1300 1580 0.6 2.6 -.7 4.1 -7.5 7.8 -40                                    1327 1300 1430 0.7 2.5 -7.4 4.2 -7.5 7.8 -36                                   1328 1280 1430 0.6 2.5 -7.5 4.1 -7.8 8 -36                                     1329 1280 1440 0.6 2.3 -7.6 4 -7.7 8 -36                                       1330 1300 1430 0.7 2.7 -7.3 3.8 -7.8 8.1 -36                                   1331 1300 1340 0.6 2.6 -7.1 4 -7.9 8.2 -26                                   __________________________________________________________________________                Product CR (Ω · F)                                                                  Insulation                                                                           Humidity                                             315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC reject                                                                               (h)                                 __________________________________________________________________________            1316                                                                               4900 4660 230  220  12 14 0/72  970                                   1317 4960 4710 220 210 13 15 0/72 960                                          1318 5000 4750 250 240 12 14 0/72 850                                          1319 5100 4850 210 200 12 14 0/72 840                                          1320 5120 4860 190 180 12 14 0/72 900                                          1321 5070 4820 200 190 12 14 0/72 890                                          1322 5200 4940 250 240 13 15 0/72 910                                          1323 5230 4970 250 240 13 15 0/72 870                                          1324 5260 5000 210 200 12 14 0/72 860                                          1325 5100 4850 190 180 12 14 0/72 890                                          1326 5020 4770 190 180 12 14 0/72 950                                          1327 5110 4860 230 220 13 15 0/72 930                                          1328 4980 4730 250 240 12 14 0/72 900                                          1329 5080 4830 190 180 12 14 0/72 890                                          1330 5060 4810 200 190 13 15 0/72 910                                          1331 4990 4740 200 190 12 14 0/72 880                                        __________________________________________________________________________

As evident from TABLE 26 and TABLE 27, the ceramic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -40% at an impressed DC voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 4900 Ω•F or more and 190 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +αM₂ O₃ +γBaZrO₃ +g MnO (wherein M₂ O₃ represents at least one of either Sc₂ O₃ and Y₂ O₃, α, γ, and g representing mole ratio, respectively), an M₂ O₃ content α of less than about 0.001 as shown in the sample No. 1301 is not preferable because the temperature characteristic does not satisfy the B-level/X7R characteristics. On the other hand, an M₂ O₃ content α of more than about 0.06 as shown in the sample No. 1302 is also not preferable because the specific dielectric constant is reduced to less than 900. Accordingly, the preferable range of the M₂ O₃ content α is 0.001≦α≦0.06.

It is not preferable that the BaZrO₃ content γ of zero as in the sample No. 1303 is not preferable since the insulation resistance is low and the voltage dependency of the insulating resistance is larger than that of the composition system containing BaZrO₃. It is also not preferable that the BaZrO₃ content γ is more than about 0.06 as in the sample No. 1304 because the temperature characteristic does not satisfy the B-level/X7R characteristics, along with shortening the mean life span. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦y≦0.06.

It is not preferable that, as seen in the sample No. 1305, the MgO content g is about 0.001 since measurements becomes impossible due to semiconductor formation. It is not preferable that the MgO content g exceeds about 0.13 as in the sample No. 1306, because the temperature characteristic does not satisfy the X7R characteristic and the insulation resistance is low and mean life span is shortened. Accordingly, the preferable range of the MgO content g is in the range of 0.00<m≦0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 1307 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample No. 1308, the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage becomes low along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 as in the samples No. 1309 and 1310 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m≦1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 1311 and 1313 because measurements are impossible due to insufficient sintering. It is not preferable that the amount of addition of the first or second side component exceeds about 3.0 parts by weight as seen in the samples No. 1312 and 1314, on the other hand, because the dielectric loss exceeds 1.0% and the insulation resistance and insulation breakdown voltage are lowered along with shortening the mean life span. Accordingly, the preferable content of either the first or the second components is in the range of 0.2 to 3.0 parts by weight.

The content of the alkali earth metal oxides contained in barium titanate as impurities is below about 0.02% by weight because, as in the sample No. 1315, when the contents of the alkali earth metal oxides exceeds about 0.02% by weight, the dielectric constant is decreased.

Example 11

A material with a composition of BaO₁.010 •TiO₂ +0.02Y₂ O₃ +0.01BaZrO₃ +0.04 MnO (mole ratio) was prepared using barium titanate A in TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 7, except that an oxide represented by Li₂ O--(Si,Ti)O₂ --MO as shown in Table 18, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the first side component. The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 7. The electric characteristics were then measured by the same method as in Example 7. The results are shown in TABLE 28. The sample No.1401 to 1422 in TABLE 28 correspond to the samples NO. 1101 to 1122 in TABLE 28, respectively. For example, the sample No. 1401 in TABLE 28 was obtained by adding the side component of the sample No. 1101 in TABLE 18.

                                      TABLE 28                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       1401 1280 1420 0.7 2.4 -8.1 3.2 -8.3 8.5 -35                                   1402 1300 1430 0.6 2.2 -8.3 3.7 -8.5 8.7 -37                                   1403 1280 1460 0.6 2.4 -7.8 4   -8.1 8.3 -36                                   1404 1300 1480 0.7 2.1 -7.9 4.1 -8   8.2 -37                                   1405 1300 1440 0.7 2.1 -7.8 3.7 -8.2 8.4 -36                                   1406 1300 1440 0.7 2.6 -8.1 3.6 -8.5 8.8 -36                                   1407 1300 1430 0.8 2.7 -8.5 3.7 -8.5 8.8 -35                                   1408 1280 1450 0.6 2.9 -8.4 4   -8.5 8.8 -37                                   1409 1280 1470 0.7 2.5 -7.9 4.1 -8.1 8.4 -36                                   1410 1280 1480 0.6 2.6 -7.6 3.7 -8.3 8.5 -37                                   1411 1300 1430 0.7 2.5 -7.5 3.8 -8.2 8.3 -35                                   1412 1280 1420 0.6 2.3 -8   3.7 -8.4 8.5 -35                                 1413                                                                               1350 Unmeasurable due to insufficient sintering                              1414 1350 Unmeasurable due to insufficient sintering                         1415                                                                               1350 1450 1.5   2.7 -7.9                                                                               4   -8  8.4  -37                                   1416                                                                               1350 Unmeasurable due to insufficient sintering                              1417 1350 Unmeasurable due to insufficient sintering                         1418                                                                               1300 1430 0.8   2.8 -8  4.2 -8.2                                                                               8.6  -35                                     1419 1350 1440 1.5 2.6 -8.1 4   -8.3 8.5 -36                                   1420 1300 1460 0.7 2.6 -8.3 3.9 -8   8.5 -37                                   1421 1350 1450 1.5 2.4 -8.2 3.7 -8.2 8.7 -37                                   1422 1350 1460 1.3 2.4 -8.3 3.7 -8.5 8.7 -37                                 __________________________________________________________________________                Product CR (Ω · F)                                                                  Insulation                                                                           Humidity                                             315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC reject                                                                               (h)                                 __________________________________________________________________________            1401                                                                               4950 4700 210  200  12 14 0/72  900                                   1402  4980 4730 220 210 13 15 0/72 910                                         1403  5100 4850 200 190 12 14 0/72 860                                         1404  5000 4750 230 220 12 15 0/72 870                                         1405  5080 4830 220 210 13 14 0/72 880                                         1406  5070 4820 200 190 13 15 0/72 910                                         1407  5120 4860 210 200 13 14 0/72 930                                         1408  5160 4900 210 200 12 14 0/72 970                                         1409  5000 4750 200 190 12 14 0/72 900                                         1410  5140 4880 220 210 13 14 0/72 880                                         1411  5100 4850 210 200 13 15 0/72 890                                         1412  5120 4860 200 190 12 14 0/72 930                                              1413                                                                               Unmeasurable due to insufficient sintering                            1414 Unmeasurable due to insufficient sintering                                     1415                                                                               4900 4660 180  170  170                                                                               13 45/72 140                                        1416                                                                               Unmeasurable due to insufficient sintering                            1417 Unmeasurable due to insufficient sintering                                     1418                                                                               5030 4780 200  190  11 14 0/72  900                                   1419 4980 4730 190 180 11 13 23/72  130                                        1420 5000 4750 200 190 12 13 0/72 880                                          1421 4970 4720 190 180 11 13 39/72  150                                        1422 4990 4740 190 180 11 13 36/72  160                                      __________________________________________________________________________

As is evident from the samples no. 1401 to 1412, 1418 and 1420 in TABLE 28, preferable results are obtained in the samples in which oxides of the samples No. 1101 to 1112, 1118 and 1120 in TABLE 18 with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0) (wherein x, y and z represent mole %, w represent mole ratio and w is in the range of 0.3≦w <1.0 in the composition on the line A-F) inside of the three component phase diagram of the oxides represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO shown in FIG. 4 are added as side components, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 4900 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

On the contrary, when the oxide represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO is outside of the composition range described above as shown in the samples No. 1113 to 1117, and 1119 in TABLE 18, the sintering becomes insufficient or many samples are rejected in the humidity resistance load test even after sintering as seen in the samples NO. 1413 to 1417 and 1419 in TABLE 28. The samples with the composition falling on the line A-F and w=1.0 as in the samples No. 1119 and 1121 in TABLE 18 have high sintering temperature along with causing many rejects in the humidity resistance load test as seen in the samples No. 1419 and 1421 in TABLE 26. When the value of w is less than 0.30 as shown in the samples No. 11 22 in TABLE 18, the sintering temperature becomes high along with causing many rejects in the humidity resistance load test as seen in the sample No. 1422 in TABLE 28.

Example 12

A material with a composition of BaO₁.010 •TiO₂ +0.02Sc₂ O₃ +0.01BaZrO₃ +0.04 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 7, except that an oxide represented by SiO₂ --TiO₂ --XO shown in Table 20, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the second side component. The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 7. The electric characteristics were then measured by the same method as in Example 7. The results are shown in TABLE 27. In TABLE 27, the samples NO. 1501 to 1519 corresponds to the samples NO. 1201 to 1219 in TABLE 22. For example, the sample No. 1501 in TABLE 29 was obtained by adding the side component of the sample No. 1201 in TABLE 22.

                                      TABLE 29                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       1501 1300 1440 1    2.3 -7.3 2.3 -7.6 8   -35                                  1502 1300 1430 1.1 2.2 -7.2 2.2 -7.8 8.2 -35                                   1503 1300 1460 1.2 2.1 -7.7 2.1 -7.7 8.1 -36                                   1504 1300 1420 1.1 2.1 -7.6 2.3 -7.8 8.2 -34                                   1505 1300 1470 1   2.3 -7.4 2.2 -7.6 8.1 -37                                   1506 1300 1450 1.2 2.2 -7.2 2.1 -7.9 8.2 -36                                   1507 1300 1420 1.2 2.3 -7.3 2.3 -7.9 8.2 -34                                   1508 1300 1430 1.2 2.3 -7.5 2.4 -8.1 8.2 -35                                   1509 1300 1440 1.1 2.1 -7.2 2.3 -7.8 8.2 -35                                   1510 1300 1480 1.2 2.2 -7.3 2.4 -8   8.1 -37                                   1511 1300 1460 1.1 2.3 -7.1 2.4 -7.8 8.3 -36                                   1512 1300 1440 1.2 2.4 -7.3 2.3 -7.6 8.1 -35                                   1513 1350 1420 1.1 2.3 -7.2 2 -7.7 8.1 -34                                   1514                                                                               1350 Unmeasurable due to insufficient sintering                              1515 1350 Unmeasurable due to insufficient sintering                         1516                                                                               1350 1430 1.2   2.2 -7.3                                                                               2.5 -7.7                                                                               8.1  -34                                   1517                                                                               1350 Unmeasurable due to insufficient sintering                              1518 1350 Unmeasurable due to insufficient sintering                           1519 1350 Unmeasurable due to insufficient sintering                         __________________________________________________________________________                Product CR (Ω · F)                                                                  Insulation                                                                           Humidity                                             315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC rejects                                                                              (h)                                 __________________________________________________________________________            1501                                                                               4950 4700 190  180  13 15 0/72  920                                   1502  4970 4720 200 190 12 14 0/72 890                                         1503  5000 4750 190 180 13 15 0/72 920                                         1504  5020 4770 230 220 13 15 0/72 960                                         1505  4960 4710 200 190 12 14 0/72 880                                         1506  5100 4850 200 190 12 15 0/72 940                                         1507  5020 4770 200 190 12 14 0/72 950                                         1508  5060 4810 230 220 12 14 0/72 870                                         1509  5050 4800 210 200 12 14 0/72 890                                         1510  5020 4770 200 190 12 14 0/72 900                                         1511  5290 5030 310 300 13 15 0/72 960                                         1512  5300 5040 320 300 12 14 0/72 950                                         1513  4820 4580 210 200 11 13 46/72  150                                            1514                                                                               Unmeasurable due to insufficient sintering                            1515 Unmeasurable due to insufficient sintering                                     1516                                                                               4790 4550 210  200  11 13 72/72 130                                        1517                                                                               Unmeasurable due to insufficient sintering                            1518 Unmeasurable due to insufficient sintering                                1519 Unmeasurable due to insufficient sintering                              __________________________________________________________________________

As is evident from Samples NO. 1501 to 1512 in TABLE 29, preferable results are obtained in the samples, in which oxides of the samples NO. 1201 to 1212 in TABLE 20 with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60), (wherein x, y and z represent mole %), of the three component phase diagram of the oxides represented by SiO₂ --TiO₂ --XO shown in FIG. 5 are added as a side component, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 4900 Ω•F or more and 190 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more and no rejections were found in the humidity resistance load test besides enabling a relatively low firing temperature of 1300° C. or less.

When the oxide SiO₂ --TiO₂ --XO has a composition outside of the composition described above as in the samples No. 1213 to 1219 in TABLE 20, on the contrary, sintering becomes insufficient or many rejection appear in the humidity resistance load test even after sintering as seen in the samples No. 1513 to 1519 in TABLE 27.

While a monolithic capacitor having, an insulation resistance of 5290 Ω•F or more and 310 Ω•F or more at 25° C. and 150° C., respectively, under a strong electric field of 10 kV/mm can be obtained as shown in the samples No. 1511 and 1512 in TABLE 29 by allowing Al₂ O₃ and/or ZrO₂ in the SiO₂ --TiO--XO oxides as in the sample No. 1211 and 1212 in Table 20, sintering property is extremely decreased when Al₂ O₃ and ZrO₂ are added in an amounts of about 15 parts by weight or more and about 5 parts by weight or more, respectively, as in the samples No. 1217 and 1218 in TABLE 20.

Example 13

After preparing and weighing TiCl₄ and Ba(NO₃)₂ having a variety of purity as starting materials, the compounds were precipitated as titanyl barium oxalate (BaTiO(C₂ O₄)•4H₂ O) by adding oxalic acid. This precipitate was decomposed by heating at a temperature of 1000° C. or more to synthesize four kinds of barium titanate listed in TABLE 1.

Oxides, carbonates or hydroxides of each component of the first side component were weighed so as to be a composition ratio (mole ratio) of 0.25Li₂ O-0.65(0.30TiO₂ -0.70SiO₂)-0.10Al₂ O₃ to obtain a powder by crushing and mixing.

Likewise, oxides, carbonates or hydroxides of each component of the second side component were weighed so as to be a composition ratio (mole ratio) of 0.66SiO₂ -0.17TiO₂ --0.15BaO-0.02MnO (mole ratio) to obtain a powder by crushing and mixing.

Oxide powders of the first and second side components were placed in separate platinum crucibles and heated at 1500° C. After quenching and crushing the mixture, each oxide powder with a mean particle size of 1 μm or less was obtained.

In the next step, BaCO₃ for adjusting the mole ratio Ba/Ti (m) in barium titanate, Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O.sub.₃, Yb₂ O₃, and BaZrO₃, MgO and MnO, each having a purity of 99% or more, were prepared. These raw material powders and the first or second side component were weighted so as to form compositions shown in TABLE 30 and TABLE 31. The amounts of addition of the first and second side components are indicated by parts by weight relative to 100 parts by weight ofthe essential component (BaO)_(m) TiO₂ +βR₂ O₃ +γBaZrO₃ +gMnO+hMgO.

                                      TABLE 30                                     __________________________________________________________________________     (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZrO.su     b.3 + γMgO + gMnO                                                        Sample                                                                             Kind of                                                                             α                                                               No. BaTiO.sub.3                                                                         Eu.sub.2 O.sub.3                                                                   Gd.sub.2 O.sub.3                                                                   Tb.sub.2 O.sub.3                                                                   Dy.sub.2 O.sub.3                                                                   Ho.sub.2 O.sub.3                                                                   Er.sub.2 O.sub.3                                                                   Tm.sub.2 O.sub.3                                                                   Yb.sub.2 O.sub.3                                                                   Total of α                      __________________________________________________________________________       *2001 2A 0 0.0008 0 0 0 0 0 0 0.0008                                           *2002 2A 0 0 0 0.04 0.03 0 0 0 0.07                                            *2003 2A 0 0.02 0.02 0 0 0 0 0 0.04                                            *2004 2A 0 0 0 0.03 0 0 0 0 0.03                                               *2005 2A 0.02 0 0 0 0 0 0 0 0.02                                               *2006 2A 0 0.02 0.03 0 0 0 0 0.01 0.06                                         *2007 2A 0 0 0 0 0.01 0 0.01 0 0.02                                            *2008 2A 0 0 0 0.04 0 0.02 0 0 0.06                                            *2009 2A 0 0.04 0.01 0.01 0 0 0 0 0.06                                         *2010 2A 0 0 0 0 0.02 0 0 0 0.02                                               *2011 2A 0.03 0 0 0 0 0 0 0 0.03                                               *2012 2A 0.01 0 0 0 0 0 0 0 0.01                                               *2013 2A 0 0.02 0 0 0 0 0 0 0.02                                               *2014 2A 0 0 0.02 0 0 0 0 0 0.02                                               *2015 2A 0 0 0.01 0.02 0 0 0 0 0.03                                            *2016 2A 0 0 0 0.02 0 0 0 0 0.02                                               *2017 2A 0 0.01 0 0 0 0 0 0 0.01                                               *2018 2D 0 0 0 0.03 0 0 0 0 0.03                                                2019 2A 0.02 0.01 0 0.02 0 0 0 0 0.05                                          2020 2B 0 0 0 0.02 0 0 0 0 0.02                                                2021 2C 0 0 0.02 0 0 0 0 0 0.06                                                2022 2A 0.05 0 0 0 0 0 0 0.01 0.06                                             2023 2A 0.01 0.01 0 0.04 0 0 0 0 0.06                                       __________________________________________________________________________                                  Amount of                                                                              Amount of                                   addition of the addition of the                                              Sample                                                                             (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZr         O.sub.3 + γMgO + gMnO                                                                             first component                                                                        second component                          No. β                                                                              γ                                                                            g      γ + g                                                                       m     (parts by weight)                                                                      (parts by weight)                         __________________________________________________________________________     *2001                                                                              0.02 0.0015                                                                             0.0015 0.003                                                                             1.005 1       0                                           *2002 0.03 0.04 0.09 0.13 1.01 1 0                                             *2003 0 0.04 0.038 0.078 1.01 1.5 0                                            *2004 0.08 0.03 0.02 0.05 1.01 1.5 0                                           *2005 0.02 0.001 0.039 0.04 1.01 1 0                                           *2006 0.02 0.125 0.005 0.13 1.01 1.5 0                                         *2007 0.03 0.039 0.001 0.04 1.01 1 0                                           *2008 0.02 0.005 0.125 0.13 1.01 1 0                                           *2009 0.03 0.04 0.1 0.14 1.01 1 0                                              *2010 0.03 0.02 0.03 0.05 0.99 1 0                                             *2011 0.04 0.03 0.02 0.05 1.00 1 0                                             *2012 0.04 0.015 0.005 0.02 1.038 1 0                                          *2013 0.02 0.02 0.03 0.05 1.05 0 1                                             *2014 0.02 0.02 0.01 0.03 1.01 0 0                                             *2015 0.03 0.02 0.03 0.05 1.01 5 0                                             *2016 0.02 0.03 0.01 0.04 1.01 0 0                                             *2017 0.02 0.015 0.005 0.02 1.01 0 4                                           *2018 0.03 0.03 0.02 0.05 1.01 2 0                                              2019 0.02 0.05 0.07 0.12 1.015 1 0                                             2020 0.03 0.02 0.01 0.03 1.02 1 0                                              2021 0.03 0.12 0.002 0.122 1.03 1.5 0                                          2022 0.03 0.06 0.07 0.13 1.02 1 0                                              2023 0.03 0.002 0.12 0.122 1.01 0 1                                         __________________________________________________________________________

                                      TABLE 31                                     __________________________________________________________________________          (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZ          rO.sub.3 + γMgO + gMnO                                              Sample                                                                             Kind of                                                                             α                                                               No. BaTiO.sub.3                                                                         Eu.sub.2 O.sub.3                                                                   Gd.sub.2 O.sub.3                                                                   Tb.sub.2 O.sub.3                                                                   Dy.sub.2 O.sub.3                                                                   Ho.sub.2 O.sub.3                                                                   Er.sub.2 O.sub.3                                                                   Tm.sub.2 O.sub.3                                                                   Yb.sub.2 O.sub.3                                                                   Total of α                      __________________________________________________________________________     2024                                                                               2A   0   0   0   0.001                                                                              0   0   0   0   0.001                                   2025 2A 0 0 0.01 0 0 0.01 0 0 0.02                                             2026 2A 0 0 0 0.02 0 0 0.01 0 0.03                                             2027 2A 0.02 0 0 0 0.02 0 0 0 0.04                                             2028 2A 0 0.05 0 0 0 0 0 0 0.05                                                2029 2A 0 0.02 0 0.04 0 0 0 0 0.06                                             2030 2A 0 0 0 0.01 0 0.01 0 0 0.02                                             2031 2A 0 0 0 0.01 0 0 0.01 0 0.02                                             2032 2A 0 0.02 0 0 0 0.01 0 0 0.03                                             2033 2A 0 0.01 0 0.01 0 0 0 0 0.02                                             2034 2A 0 0 0.01 0 0 0 0 0 0.01                                                2035 2A 0 0 0 o.01 0 0 0 0 0.01                                                2036 2A 0.01 0 0 0.01 0 0 0 0 0.02                                           __________________________________________________________________________                                  Amount of                                                                              Amount of                                   addition of the addition of the                                              Sample                                                                             (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZr         O.sub.3 + γMgO + gMnO                                                                             first component                                                                        second component                          No. β                                                                              γ                                                                            g      γ + g                                                                       m     (parts by weight)                                                                      (parts by weight)                         __________________________________________________________________________     2024                                                                               0.02 0.0015                                                                             0.0015 0.003                                                                             1.01  1       0                                           2025 0.02 0.02 0.03 0.05 1.01 1 0                                              2026 0.02 0.03 0.02 0.05 1.015 0 1                                             2027 0.02 0.03 0.05 0.08 1.01 0 1                                              2028 0.02 0.05 0.06 0.11 1.01 1 0                                              2029 0.02 0.06 0.062 0.122 1.01 1 0                                            2030 0.005 0.02 0.03 0.05 1.01 1 0                                             2031 0.06 0.02 0.02 0.04 1.01 1 0                                              2032 0.03 0.02 0.04 0.06 1.035 2 0                                             2033 0.03 0.02 0.03 0.05 1.015 0.2 0                                           2034 0.02 0.01 0.012 0.022 1.01 3 0                                            2035 0.03 0.015 0.005 0.02 1.01 0 0.2                                          2036 0.03 0.02 0.03 0.05 1.01 0 3                                            __________________________________________________________________________

An organic solvent such as polyvinyl butyral binder and ethanol was added to the weighed compounds, which were mixed in a ball mill in an wet state to prepare a ceramic slurry. This ceramic slurry was formed into a sheet by a doctor blade method to obtain a rectangular shaped green sheet with a thickness of 35 μm, followed by printing an electroconductive paste mainly composed of Ni on the ceramic green sheet to form an electroconductive paste layer for forming inner electrodes.

Then, a plurality of the ceramic green sheets on which the electroconductive layer is formed were laminated so that the sides where the electroconductive paste projected are alternately placed, thus obtaining a monolithic body. This monolithic body was heated at 350° C. in a N₂ atmosphere and, after allowing the binder to decompose, the monolithic body was fired at the temperatures shown in TABLE 32 and TABLE 33 in a reducing atmosphere comprising H₂ --N₂ --H₂ O gases under an oxygen partial pressure of 10⁻⁹ to 10⁻¹² MPa for two hours, thereby obtaining a ceramic sintered body.

Both side faces of the ceramic sintered body were coated with a silver paste containing B₂ O₃ --Li₂ O--SiO₂ --BaO glass frit and fired at a temperature of 600° C. in a N₂ atmosphere, thereby obtaining outer electrodes electrically connected to the inner electrodes.

The overall dimensions of the monolithic ceramic capacitor thus obtained were 5.0 mm in width, 5.7 mm in length and 2.4 mm in thickness while the thickness of each dielectric ceramic layer was 30 μm. The total number of the effective dielectric ceramic layers were 57, the area of the confronting electrode per one layer being 8.2×10⁻⁶ m².

Electric characteristics of these monolithic ceramic capacitors were measured. The electrostatic capacitance (C) and dielectric loss (tan δ) were measured using an automatic bridge type measuring instrument at 1 kHz, 1 Vrms and 25° C. and the dielectric constant (ε) was calculated from the electrostatic capacitance. Next, the insulation resistance was measured using an insulation resistance tester at 25° C. and 150° C. by impressing direct current voltages of 315 V (or 10 kV/mm) and 945 V (or 30 kV/mm) for 2 minutes, obtaining a product of the electrostatic capacitance and insulation resistance, or a product CR.

The rate of change of the electrostatic capacitance against temperature changes was also measured. The rate of change at -25° C. and 85° C. by taking the electrostatic capacitance at 20° C. as a standard (ΔC/C₂₀), the rate of change at -55° C. and 125° C. by taking the electrostatic capacitance at 20° C. as a standard (ΔC/C₂₅) and the maximum value of the rate of change (|ΔC|_(max)) as an absolute value in the temperature range of -55° C. to 125° C. were measured as the electrostatic capacitances against temperature changes.

The DC vias characteristic was also evaluated. First, the electrostatic capacitance when an AC voltage of 1 kHz and 1 Vrms was impressed was measured. Then, the electrostatic capacitance when a DC voltage of 150 V and an AC voltage of 1 kHz and 1 Vrms were simultaneously impressed was measured, thereby the rate of reduction of the electrostatic capacitance (ΔC/C) due to loading the DC voltage was calculated.

In the high temperature load test, a direct current voltage of 750 V (or 25 kV/mm) was impressed at 150° C. on 36 pieces of each sample to measure the time dependent changes of the insulation resistance. The time when the insulation resistance of each sample was reduced below 10⁶ Ω was defined to be a life span time and mean life span time was evaluated.

In the humidity resistance test, the number of the test pieces having an insulation resistance of 10⁶ Ω or less among the 72 test pieces were counted after impressing a DC voltage of 315 V under an atmospheric pressure of 2 atm (relative humidity 100%) at 120° C. for 250 hours.

Insulation breakdown voltages under AC and DC voltages were measured by impressing AC and DC voltages at a voltage increase rate of 100 V/sec.

The results described above are listed in TABLE 32 and TABLE 33.

                                      TABLE 32                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       *2001 1300 2030 0.8 2.4 -8.6 4.3 -12.5 13.4 -56                                *2002 1300  860 1 3.5 14.9 6.5 -23.4 23.4 -14                                  *2003 1280 1350 0.9 3.6 -8.5 3.3 -13.4 13.4 -30                                *2004 1300 1420 1 3.5 -13.2 4 -28.6 28.6 -36                                   *2005 1280 1550 0.9 3.6 -13.2 4 -17.2 17.2 -41                                 *2006 1360 1080 2.5 2.9 -9.1 4.5 -12.8 12.8 -16                              *2007                                                                              Unmeasurable due to semiconductor formation                                *2008                                                                              1280 1060 0.8   4.2 -9.2                                                                               4.5 -18.3                                                                              18.3 -16                                     *2009 1280 1040 2.5 3.1 -9 4.1 -13.5 13.5 -15                                  *2010                                                                          *2011 1300 1460 0.9 3.4 -9.4 3.8 -13.4 13.4 -38                              *2012                                                                              Unmeasurable due to insufficient sintering                                   *2013 Unmeasurable due to insufficient sintering                               *2014 Unmeasurable due to insufficient sintering                             *2015                                                                              1300 1470 2.7   3.5 -9.3                                                                               4   -12.9                                                                              12.9 -39                                   *2016                                                                              Unmeasurable due to insufficient sintering                                 *2017                                                                              1300 1920 2.6   3.2 -9.1                                                                               3.8 -12.7                                                                              12.7 -55                                     *2018 1300 1050 0.8 3 -8.7 4.2 -13.5 13.5 -15                                   2019 1280 1230 0.7 2.8 -8.9 3.8 -12.8 12.8 -22                                 2020 1280 1560 0.8 2.7 -9 3.8 -13.6 13.6 -42                                   2021 1280 1080 0.7 2.9 -9.2 3.7 -13.5 13.5 -16                                 2022 1300 1060 0.8 3 -9.4 3.9 -13.7 13.7 -16                                   2023 1300 1070 0.7 3.2 -9 4 -13.8 13.8 -16                                  __________________________________________________________________________                Product CR (Ω · F)                                                                  Insulation                                                                           Humidity                                             315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC injects                                                                              (h)                                 __________________________________________________________________________            *2001                                                                              3040 2890 110  110  13 14 0/72  850                                   *2002  5070 4820 240 230 13 14 0/72 170                                        *2003  3020 2110 120 >80 12 14 0/72 800                                        *2004  5120 4860 210 200 12 14 0/72 120                                        *2005  3040 2890 120 110 13 14 0/72 880                                        *2006  5080 4830 220 210 12 14 49/72 180                                            2007                                                                               Unmeasurable due to semiconductor formation                                *2008                                                                              3060 2910 140  130  12 14 0/72  110                                   *2009 5080 4830 230 220 12 14 15/72  100                                       *2010                                                                          *2011 3180 3020 t70 160 10 11 0/72 190                                              *2012                                                                              Unmeasurable due to insufficient sintering                            *2013 Unmeasurable due to insufficient sintering                               *2014 Unmeasurable due to insufficient sintering                                    *2015                                                                              3160 3000 180  170  10 12 0/72  150                                        *2016                                                                              Unmeasurable due to insufficient sintering                                 *2017                                                                              3250 3090 170  160  11 11 0/72  120                                   *2018 5140 4880 250 240 13 15 0/72 850                                          2019  5080 4830 260 250 12 15 0/72 890                                         2020  5060 4810 270 260 12 14 0/72 920                                         2021  5200 4940 280 270 12 15 0/72 890                                         2022  5160 4900 260 250 12 14 0/72 850                                         2023  5220 4960 250 240 13 15 0/72 900                                      __________________________________________________________________________

                                      TABLE 33                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       2024 1300 2010 0.9 3.4 -8.9 4 -13.6 14 -56                                     2025 1300 1530 0.8 3.4 -8.7 4.1 -12.9 13 -42                                   2026 1280 1470 0.8 3 -8.8 3.9 -13 13 -38                                       2027 1280 1360 0.7 2.9 -8.9 3.8 -12.8 13 -32                                   2028 1300 1220 0.7 3.5 -9.2 3.5 -13.2 13 -22                                   2029 1300 1050 0.7 3.3 -9.3 3.8 -13.8 14 -15                                   2030 1300 1550 0.7 3.2 -9.1 3.8 -13.5 14 -41                                   2031 1280 1570 0.7 3 -9 4 -12.8 13 -41                                         2032 1280 1430 0.7 3.5 -8.9 4.1 -13 13 -37                                     2033 1300 1580 0.7 4 -8.8 3.9 -13.7 14 -41                                     2034 1300 1600 0.7 4.1 -8.7 3.9 -13.5 14 -45                                   2035 1300 1600 0.7 3.2 -9 3.5 -13.9 14 -45                                     2036 1280 1540 0.7 3.5 -8.9 3.6 -12.9 13 -43                                 __________________________________________________________________________                315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC rejects                                                                              (h)                                 __________________________________________________________________________            2024                                                                               5260 5000 250  240  12 14 0/72  830                                   2025 5280 5020 280 270 12 14 0/72 840                                          2026 5100 4850 240 230 13 14 0/72 890                                          2027 5160 4900 260 250 12 14 0/72 820                                          2028 5290 5030 230 220 13 14 0/72 870                                          2029 5060 4810 210 200 12 14 0/72 000                                          2030 5120 4860 260 250 12 14 0/72 830                                          2031 5180 4920 250 240 12 15 0/72 810                                          2032 5280 5020 250 240 12 14 0/72 860                                          2033 5160 4900 230 220 12 14 0/72 810                                          2034 5090 4840 260 250 12 14 0/72 870                                          2035 5100 4850 250 240 13 14 0/72 850                                          2036 5160 4900 280 270 13 14 0/72 880                                        __________________________________________________________________________

It is evident from Table 30 to TABLE 33 that the monolithic ceramic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of less than 1.0 %, wherein the rate of change against temperature changes satisfies both the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +βR₂ O₃ +γBaZrO₃ +gMnO+hMgO (wherein R₂ O₃ represents at least one compound selected from Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O₃ and Yb₂ O₃, β, γ, representing mole ratio, respectively), a R₂ O₃ content β of less than about 0.001 as shown in the sample No. 2001 is not preferable because the insulation resistance is low and the product CR becomes small. On the other hand, a R₂ O₃ content β of more than about 0.06 as shown in the sample No. 2002 is also not preferable because the temperature characteristic does not satisfy the B-level/X7R characteristics, being poor in reliability. Accordingly, the preferable range of the R₂ O₃ content β is 0.001≦β≦0.06.

A BaZrO₃ content γ of zero as in the sample No. 2003 is not preferable since the insulation resistance is low and the voltage dependency of the insulating resistance is larger than that of the composition system containing BaZrO₃. It is also not preferable that the BaZrO₃ content γ is more than about 0.06 as in the sample No. 2004 because the temperature characteristic does not satisfy the B-level/X7R characteristics, along with shortening the mean life span. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦γ≦0.06.

It is not preferable that, as seen in the sample No. 2005, the MgO content h is about 0.001 since the insulation resistance becomes low and the temperature characteristic does not satisfy the B-level/X7R characteristics. On the other hand, it is not preferable that the MgO content h exceeds about 0.12 as in the sample No. 2006, because the sintering temperature becomes high, the dielectric loss exceeds 2.0%, the number of rejections in the humidity resistance load test is extremely increased and with the mean life span being short. Accordingly, the preferable range of the MgO content h is in the range of 0.001≦h≦0.12.

It is not preferable that, as seen in the sample No. 2007, the MnO content g is 0.001 since measurement becomes impossible due to formation of semiconductors. It is not preferable, on the other hand, that the MnO content g exceeds about 0.12 as seen in the sample No. 2008 because the temperature characteristic X7R is not satisfied and the insulation resistance is lowered and the mean life span becomes short. Accordingly, the preferable range of the MnO content g is in the range of 0.001<g≦0.12.

It is not preferable that, as in the sample No. 2009, the combined amount of g+h of the MnO content and MgO content exceeds about 0.13 because the dielectric loss is increased to 2.0% and the mean life span is shortened and the rejection number in the humidity resistance load test increases. Accordingly, the combined amount of g+h of the MnO content and Mg content is preferably in the range of g+h≦0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 2010 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample No. 2011, the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage becomes low along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 as in the samples No. 2012 and 2013 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m≦1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 2014 and 2016 because measurements are impossible due to insufficient sintering. It is not preferable that the amount of addition of the first or second side component exceeds about 3.0 parts by weight as seen in the samples No. 2015 and 2017, on the other hand, because the dielectric loss exceeds 1.0% and the insulation resistance and insulation breakdown voltage are lowered along with shortening the mean life span. Accordingly, the preferable content of either the first or the second components is 0.2 to 3.0 parts by weight.

The content of the alkali earth metal oxides contained in barium titanate as impurities is below about 0.02% by weight because when the contents of the alkali earth metal oxides exceeds about 0.02% by weight as in the sample No. 2018, the dielectric constant is decreased.

Example 14

A material with a composition of BaO₁.010 •TiO₂ +0.03Gd₂ O₃ +0.025BaZrO₃ +0.05MgO+0.01 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 13, except that an oxide represented by Li₂ O--(Si, Ti)O₂ --MO shown in Table 34, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the first side component. The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 13.

The electric characteristics were then measured by the same as in Example 13. The results are shown in TABLE 35.

                  TABLE 34                                                         ______________________________________                                         The first side component                                                                  Amount of                                                              addition                                                                      Sample (parts by Composition (mol %, except w)                               No.    weight)  Li.sub.2 O                                                                             (Si.sub.w Ti.sub.1-w)O.sub.2                                                           w    Al.sub.2 O.sub.3                                                                     ZrO.sub.2                           ______________________________________                                         2101   1        20      80      0.3  0     0                                     2102 1 10 80 0.6 5 5                                                           2103 0.8 10 70 0.5 20  0                                                       2104 0.8 35 45 1 10  10                                                        2105 1.5 45 45 0.5 10  0                                                       2106 1.5 45 55 0.3 0 0                                                         2107 1 20 70 0.6 5 5                                                           2108 1 20 70 0.4 10  0                                                         2109 1.2 30 60 0.7 5 5                                                         2110 1.2 30 60 0.8 10  0                                                       2111 2 40 50 0.6 5 5                                                           2112 2 40 50 0.9 0 10                                                          2113 1.5 10 85 0.4 5 0                                                         2114 2  5 75 0.6 10  10                                                        2115 1.2 20 55 0.5 25  0                                                       2116 1 45 40 0.8 0 15                                                          2117 0.8 50 45 0.7 5 0                                                         2118 1.2 25 75 0.9 0 0                                                         2119 1.5 25 75 1 0 0                                                           2120 1 35 65 0.9 0 0                                                           2121 1.5 35 65 1 0 0                                                           2122 1.2 20 70 0.2 0 10                                                      ______________________________________                                    

                                      TABLE 35                                     __________________________________________________________________________                                              DC vias                                    Ratio of Temperature Dependent characteristic                               Baking  Dielectric Capacitance Change (%) (%)                                Sample                                                                             Temp.                                                                               Dielectric                                                                          Loss  ΔC/C.sub.20                                                                      ΔC/C.sub.25                                                                      Maximum                                                                             ΔC/C                            No. (° C.)                                                                       Constant                                                                            tan δ (%)                                                                      -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                               5 kV/mm                               __________________________________________________________________________       2101 1280 1430 0.8 3.6 -9 4.2 -13.4  13 -37                                    2102 1280 1460 0.8 3.8 -8.7 3.8 -13.5 14 -37                                   2103 1280 1490 0.8 4.1 -8.9 3.9 -13.6 14 -40                                   2104 1300 1420 0.8 4 -9 4 -14 14 -35                                           2105 1300 1430 0.9 3.2 -9.2 4.2 -13.8 14 -36                                   2106 1280 1400 0.8 3.6 -9.4 3.7 -13.7 14 -35                                   2107 1280 1460 0.8 3.5 -8.8 3.5 -13.9 14 -38                                   2108 1280 1460 0.8 4 -9.5 3.9 -12.8 13 -38                                     2109 1280 1420 0.9 3.8 -9.6 4.2 -12.5 13 -36                                   2110 1300 1470 0.8 3.5 -9.7 3.5 -13 13 -38                                     2111 1300 1430 0.8 3.9 -9.5 4.2 -13.8 14 -35                                   2112 1280 1420 0.8 4 -9.6 4.3 -13.6 14 -35                                   2113                                                                               1350 Unmeasurable due to insufficient sintering                              2114 1350 Unmeasurable due to insufficient sintering                         2115                                                                               1350 1230 1.8   3.5 -9.1                                                                               4   -13.8                                                                              14   -22                                   2116                                                                               1350 Unmeasurable due to insufficient sintering                              2117 1350 Unmeasurable due to insufficient sintering                         2118                                                                               1300 1480 0.9   3.8 -9.3                                                                               4.6 -13.5                                                                              14   -37                                     2119 1350 1200 1.6 3.2 -8.8 3.8 -12.9 13 -20                                   2120 1300 1450 0.9 3 -8.9 3.8 -13.7 14 -38                                     2121 1350 1210 1.4 3.8 -8.9 3.5 -13.6 14 -21                                   2122 1350 1190 1.5 3.6 -9 4 -13.5 14 -20                                     __________________________________________________________________________                Product CR (Ω · F)                                                                  Insulation                                                                           Humidity                                             315 V                                                                               945 V                                                                               315 V                                                                               945 V                                                                               breakdown                                                                            Resistance                                   Impressed Impressed Impressed Impressed voltage Load Test: Mean                                                         Sample Voltage Voltage                                                        Voltage Voltage (kV/mm) Number                                                 of Life Span                               No. 25° C.                                                                            150° C.                                                                           AC DC reject                                                                               (h)                                 __________________________________________________________________________            2101                                                                               5240 4980 240  230  12 14 0/72  850                                   2102 5130 4870 220 210 12 14 0/72 890                                          2103 5170 4910 220 210 12 14 0/72 870                                          2104 5090 4840 230 220 12 14 0/72 830                                          2105 5080 4830 220 210 13 14 0/72 840                                          2106 5100 4850 210 200 12 14 0/72 850                                          2107 5160 4900 210 200 13 14 0/72 890                                          2108 5240 4980 210 200 12 15 0/72 840                                          2109 5230 4970 210 200 12 14 0/72 830                                          2110 5200 4940 210 200 12 14 0/72 840                                          2111 5180 4920 220 210 13 14 0/72 890                                          2112 5270 5010 220 210 12 14 0/72 900                                               2113                                                                               Unmeasurable due to insufficient sintering                            2114 Unmeasurable due to insufficient sintering                                     2115                                                                               3800 3610 150  140  11 12 26/72 150                                        2116                                                                               Unmeasurable due to insufficient sintering                                 2117                                                                               Unmeasurable due to insufficient sintering                                 2118                                                                               5160 4900 220  210  12 14 0/72  860                                   2119 3860 3670 120 110 11 12 20/72  160                                        2120 5230 4970 230 220 12 14 0/72 840                                          2121 3810 3620 130 120 11 12 34/72  130                                        2122 3850 3660 100  90 11 12 29/72  180                                      __________________________________________________________________________

As is evident from TABLE 34 and TABLE 35, preferable results are obtained in the samples No. 2101 to 2112, 2118 and 2120 in which the oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=20, y=80, z=0), B (x=10, y 80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, (x=45, y=55, z=0) (wherein x, y and z represent mole % and w represents mole ratio, w being in the range of 0.3≦w<1.0 when it falls on the line A-F) of the three component phase diagram of the oxides represented by Li₂ O--(Si_(1-w), Ti_(1-w))₂ --MO shown in FIG. 4 are added, wherein the samples have a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

When the oxide represented by Li₂ O--(Si_(w) Ti_(1-w))O₂ --MO has a composition outside of the composition described above as in the samples No. 2113 to 2117 and 2119, on the other hand, sintering becomes insufficient or many rejection appear in the humidity resistance load test even after sintering. When the composition falls on the line A-F and w=1.0, the sintering temperature becomes high, giving a lot of rejections in the humidity resistance load test as shown in the samples No. 2119 and 2121. When the value of w is less than 3.0, the sintering temperature becomes so high that many rejections appear in the humidity resistance test as shown in Sample No. 2122.

Example 15

A material with a composition of BaO₁.010 @TiO₂ +0.03Dy₂ O₃ +0.02BaZrO₃ +0.05 MgO+0.01 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 13, except that an oxide represented by SiO₂ --TiO₂ --XO shown in Table 36, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500 ° C., was added as the second side component. The amounts of addition of Al₂ O₃ and ZrO₃ are indicated by parts by weight relative to 100 parts by weight of the second side component (xSiO₂ -yTiO₂ --zXO). The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 13.

The electric characteristics were then measured by the same method as in Example 13. The results are shown in TABLE 37.

                                      TABLE 36                                     __________________________________________________________________________         The second side component                                                      Amount of                                                                     addition Essential component (mol %)                                        Sample                                                                             (Parts by  XO                   Added component (Parts by weight)          N0. Weight)                                                                             SiO.sub.2                                                                         TiO.sub.2                                                                         BaO                                                                               CaO                                                                               SrO                                                                               MgO                                                                               ZnO                                                                               MnO                                                                               Total                                                                             Al.sub.2 O.sub.3                                                                        ZrO.sub.2                         __________________________________________________________________________     2201                                                                               1    85  1  1  0 0  0  4  9  14 0        0                                   2202 1 35 51  0 10 0 0 0 4 14 0 0                                              2203 1 30 20  0 30 0 15  4 1 50 0 0                                            2204 1 39  1 20 20 2 0 13  5 60 0 0                                            2205 1 70 10  5  5 0 0 10  0 20 0 0                                            2206 1 45 10  0  0 0 0 15  30  45 0 0                                          2207 1 50 20 10 10 3 7 0 0 30 0 0                                              2208 1 50 30  0 16 0 0 0 4 20 0 0                                              2209 1 35 30 25 10 0 0 0 0 35 0 0                                              2210 1 40 40 10  0 0 0 5 5 20 0 0                                              2211 1 45 22  3 30 0 0 0 0 33 15  0                                            2212 1 45 22  3 30 0 0 0 0 33 10  5                                            2213 1 65 25  5  5 0 0 0 0 10 0 0                                              2214 1 25 40 15  0 10  0 5 5 35 0 0                                            2215 1 30 10 30 25 0 0 5 0 60 0 0                                              2216 1 50  0 35 15 0 0 0 0 50 0 0                                              2217 1 45 22 30  0 0 3 0 0 33 25  0                                            2218 1 45 22 30  0 3 0 0 0 33 0 15                                             2219 1 30 60 10  0 0 0 0 0 10 0 0                                            __________________________________________________________________________

                                      TABLE 37                                     __________________________________________________________________________                                          Product CR (Ω · F)                                              315                                                                               945        Insula-                                                                             Humid-                        DC vias V V   tion ity                                                       Di-  charac- Im- Im-   break- Resis-                                          Di- elec- Ratio of Temperature Dependent teristic press- press- 315 V                                                                  945 V down                                                                     tance                                                                             elec- tric                                                                  apacitance                                                                     Change (%)                                                                     (%) ed ed Im-                                                                  Im- voltage                                                                    Load Mean          Sam-                                                                              Baking                                                                             tric                                                                              Loss               Maxi-                                                                              ΔC/C                                                                         Volt-                                                                             Volt-                                                                             pressed                                                                            pressed                                                                            (kV/ Test                                                                               Life                 ple Temp. Con- tan ΔC/C.sub.20 ΔC/C.sub.25 mum 5 k age age                                                                   Voltage                                                                        Voltage mm)                                                                    Number Span        No.                                                                               (° C.)                                                                      stant                                                                             δ (%)                                                                       -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                              V/mm                                                                               25° C.                                                                        150° C.                                                                         AC DC                                                                               of reject                                                                          (h)                __________________________________________________________________________     2101                                                                              1300                                                                               1040                                                                              0.7                                                                               3.4 -9.5                                                                               3.6 -13.9                                                                              14  -16 5070                                                                              4820                                                                              210 200 13 15                                                                               0/72                                                                               880                  2102 1280 1060 0.7 3.5 -8.9 4 -14.2 14 -17 5090 48A0 210 200 12 14 0/72                                                                  850                  2103 1280 1100 0.7 3.8 -9.1 3.9 -13.8 14 -18 5100 4850 220 210 12 15                                                                     0/72 800                                                                        2104 1300                                                                     1070 0.7 4 -9                                                                  4.2 -13.5 14                                                                   -17 5120 4860                                                                  210 200 12 14                                                                  0/72 900                                                                        2105 1300                                                                     1020 0.7 4.2                                                                   -9.2 4.3                                                                       -13.6 14 -15                                                                   5130 4870 210                                                                  200 13 14                                                                      0/72 920                                                                        2106 1280                                                                     1080 0.7 3.9                                                                   -8.8 4.5                                                                       -13.7 14 -17                                                                   5080 4830 230                                                                  220 13 15                                                                      0/72 840                                                                        2107 1280                                                                     1100 0.7 3.4                                                                   -8.7 4.5 -14                                                                    14 -18 5080                                                                   4830 210 200                                                                   12 14 0/72                                                                     860                  2108 1300 1060 0.7 3.6 -8.9 4.2 -13.5 14 -17 5120 4860 220 210 12 14                                                                     0/72 920                                                                        2109 1300                                                                     1090 0.7 4.1                                                                   -8.8 4 -13.6                                                                   14 -18 5160                                                                    4900 220 210                                                                   12 14 0/72                                                                     900                  2t10 1300 1050 0.7 3.8 -9 4.3 -13.7 14 -17 5150 4890 210 200 12 14 0/72                                                                  880                  2111 1280 1070 0.7 3.9 -9.2 4.2 -13.3 13 -17 5430 5160 310 300 12 15                                                                     0/72 870                                                                        2112 1300                                                                     1080 0.7 4                                                                     -9.4 4 -13.5                                                                   14 -18 5450                                                                    5180 320 300                                                                   12 14 0/72                                                                     900                  2113 1350  860 1.4 3.5 -8.7 3.9 -13.6 14 -14 3790 3600 150 140 11 13                                                                     45/72 160          2114                                                                              1350                                                                               Unmeasurable due to insufficient sintering                                2115 1350 Unmeasurable due to insufficient sintering                         2116                                                                              1350                                                                                830                                                                              1.3                                                                               3.6 -8.8                                                                               3.9 -13.7                                                                              14  -14 3860                                                                              3670                                                                              130 120 11 12                                                                               68/72                                                                              180                2117                                                                              1350                                                                               Unmeasurable due to insufficient sintering                                2118 1350 Unmeasurable due to insufficient sintering                           2119 1350 Unmeasurable due to insufficient sintering                         __________________________________________________________________________

As is evident from TABLE 36 and TABLE 37, preferable results are obtained in the samples No. 2201 to 2212, in which oxides with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60), (wherein x, y and z represent mole %), of the three component phase diagram of the oxides represented by SiO₂ --TiO₂ --XO shown in FIG. 5 are added, wherein the samples have a capacitance decreasing ratio of as small as within -45% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more and no rejections were found in the humidity resistance load test besides enabling a relatively low firing temperature of 1300° C. or less.

When the oxide represented by SiO₂ --TiO₂ --XO has a composition outside of the composition described above as in the samples No. 2114, 2115 and 2117 to 2119, on the contrary, sintering becomes insufficient or many rejection appear in the humidity resistance load test even after sintering.

While a monolithic capacitor having an insulation resistance of 5400 Ω•F or more and 300 Ω•F or more at 25° C. and 150° C., respectively, under a strong electric field of 10 kV/mm can be obtained by allowing Al₂ O₃ and/or ZrO₂ in the SiO₂ --TiO₂ --XO oxides as in the sample No. 2211 and 2212, the sintering, property is extremely decreased when Al₂ O₃ and ZrO₂ are added in an amounts of about 15 parts by weight or more and about 5 parts by weight or more, respectively, as in the samples No. 2217 and 2218.

Example 16

Four kinds of barium titanate (BaTiO₃), an oxide powder as a first side component and an oxide powder as a second side component were obtained by the same method as in Example 13.

Then, BaCO₃ for adjusting the mole ratio Ba/Ti in barium titanate, Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O₃ and Yb₂ O₃, and MnO, each having a purity of 99% or more, were prepared. These raw material powders and the oxides described above as either the first or the second component were weighed so as to be the composition in TABLE 38 and TABLE 39. The amounts of addition of the first and second side components are defined by the amount of addition relative to 100 parts by weight of (BaO)_(m) TiO₂ +αR₂ O₃ +γBaZrO₃ +gMnO. A monolithic ceramic capacitor was produced by the same method as in Example 13 using these weighed materials. The overall dimensions of the monolithic ceramic capacitor are the same as in Example 13.

                                      TABLE 38                                     __________________________________________________________________________                                                            Amount                                                                             Amount                                                                          of of                                                                          addition                                                                      addition                                                                        of the of the        first second                                                                   com- com-                                                                      ponent ponent                                                                    (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZr         O.sub.3 + γMnO                               (parts                                                                             (parts              Sample                                                                             Kind of                                                                            α                                        by  by                  No. BaTiO.sub.3                                                                        Eu.sub.2 O.sub.3                                                                   Gd.sub.2 O.sub.3                                                                   Tb.sub.2 O.sub.3                                                                   Dy.sub.2 O.sub.3                                                                   Ho.sub.2 O.sub.3                                                                   Er.sub.2 O.sub.3                                                                   Tm.sub.2 O.sub.3                                                                   Yb.sub.2 O.sub.3                                                                   Total of α                                                                    β                                                                            γ                                                                            m  weight)                                                                            weight)             __________________________________________________________________________     *2301                                                                              A   0   0.0007                                                                             0   0   0   0   0   0   0.0007                                                                              0.03                                                                              0.0014                                                                             1.005                                                                             1   0                     *2302 A 0 0 0.02 0 0.055 0 0 0 0.075 0.02 0.0128 1.01 1 0                      *2303 A 0.01 0 0 0.025 0 0 0 0 0.035 0 0.07 1.015 2 0                          *2304 A 0 0.01 0 0 0.01 0 0.01 0 0.03 0.07 0.06 1.01 2.5 0                     *2305 A 0.04 0 0 0 0 0 0 0 0.04 0.025 0.001 1.01 1 0                           *2306 A 0 0 0 0.02 0 0.03 0 0 0.05 0.03 0.145 1.01 1 0                         *2307 A 0 0 0.02 0 0 0 0 0.01 0.03 0.03 0.06 0.99 0 1                          *2308 A 0 0.01 0 0.01 0 0 0 0 0.02 0.03 0.04 1 2 0                             *2309 A 0 0 0 0 0 0 0.01 0 0.01 0.03 0.02 1.037 1 0                            *2310 A 0.01 0.01 0 0 0 0 0 0 0.02 0.03 0.04 1.045 0 2                         *2311 A 0 0 0 0 0.01 0 0 0 0.01 0.02 0.02 1.01 0 0                             *2312 A 0 0.02 0 0 0 0.02 0 0 0.04 0.03 0.08 1.01 4 0                          *2313 A 0 0 0.01 0.01 0 0 0 0 0.02 0.04 0.04 1.015 0 0                         *2314 A 0.01 0 0 0 0 0 0 0.01 0.02 0.02 0.04 1.01 0 5                          *2315 D 0 0 0 0 0.02 0 0 0 0.02 0.04 0.04 1.01 2 0                             2316 A 0 0.02 0.02 0 0 0 0 0 0.04 0.02 0.08 1.01 0 1                           2317 B 0 0 0.01 0 0 0.01 0 0 0.02 0.03 0.04 1.02 1 0                         __________________________________________________________________________

                                      TABLE 39                                     __________________________________________________________________________                                                            Amount                                                                             Amount                                                                          of of                                                                          addition                                                                      addition                                                                        of the of the        first second                                                                   com- com-                                                                      ponent ponent                                                                    (BaO).sub.m · TiO.sub.2 + αR.sub.2 O.sub.3 + βBaZr         O.sub.3 + γMnO                               (parts                                                                             (parts              Sample                                                                             Kind of                                                                            α                                        by  by                  No. BaTiO.sub.3                                                                        Eu.sub.2 O.sub.3                                                                   Gd.sub.2 O.sub.3                                                                   Tb.sub.2 O.sub.3                                                                   Dy.sub.2 O.sub.3                                                                   Ho.sub.2 O.sub.3                                                                   Er.sub.2 O.sub.3                                                                   Tm.sub.2 O.sub.3                                                                   Yb.sub.2 O.sub.3                                                                   Total of α                                                                    β                                                                            γ                                                                            m  weight)                                                                            weight)             __________________________________________________________________________     2318                                                                               C   0.03                                                                               0   0   0   0   0   0   0   0.03 0.02                                                                              0.013                                                                              1.03                                                                              2   0                     2319 A 0 0 0 0.01 0 0 0.02 0 0.03 0.02 0.06 1.015 1 0                          2320 A 0 0.04 0 0 0 0 0 0 0.04 0.03 0.08 1.02 0 2                              2321 A 0 0.001 0 0 0 0 0 0 0.001 0.02 0.002 1.01 1 0                           2322 A 0 0 0.01 0.01 0 0 0 0.01 0.03 0.03 0.06 1.01 1 0                        2323 A 0 0 0 0 0 0.02 0 0 0.02 0.02 0.04 1.025 0 1                             2324 A 0 0.01 0 0 0.03 0 0 0 0.04 0.02 0.08 1.01 0 1                           2325 A 0 0 0 0.02 0 0 0.02 0 0.04 0.03 0.08 1.01 1 0                           2326 A 0 0.03 0 0 0 0.03 0 0 0.06 0.03 0.12 1.02 2 0                           2327 A 0 0 0.01 0 0 0 0.02 0 0.03 0.005 0.06 1.01 1 0                          2328 A 0 0 0 0.01 0.01 0 0 0 0.02 0.06 0.04 1.01 1 0                           2329 A 0 0 0.01 0 0 0.01 0 0 0.02 0.02 0.04 1.035 2 0                          2330 A 0 0 0 0 0 0 0.o3 0 0.03 0.03 0.06 1.01 0.2 0                            2331 A 0.01 0 0.01 0 0 0 0 0 0.02 0.02 0.04 1.01 3 0                           2332 A 0 0 0 0.01 0 0 0 0.01 0.02 0.04 0.04 1.01 0 0.2                         2333 A 0 0 0 0 0 0.02 0 0 0.02 0.03 0.04 1.01 0 3                            __________________________________________________________________________

The electric characteristics were measured by the same method as in Example 13. The results are shown in TABLE 40 and TABLE 41.

                                      TABLE 40                                     __________________________________________________________________________                                          Product CR (Ω · F)                                               315                                                                               945                                                                               315    Insula-                                                                             Humid-                        DC vias V V V  tion ity                                                      Di-  charac- Im- Im- Im-  break- Resis-                                       Di- elec- Ratio of Temperature Dependent teristic press- press-                                                                        press- 945 V                                                                   down tance                                                                        elec- tric                                                                  apacitance                                                                     Change (%)                                                                     (%) ed sed ed                                                                  Im- voltage                                                                    Load Mean          Sam-                                                                               Baking                                                                             tric                                                                              Loss               Maxi-                                                                              ΔC/C                                                                         Volt-                                                                             Volt-                                                                             Volt-                                                                             pressed                                                                            (kV/ Test                                                                               Life                 ple Temp. Con- tan ΔC/C.sub.20 ΔC/C.sub.25 mum 5 k age age                                                                   age Voltage                                                                    mm) Number                                                                     Span               No. (° C.)                                                                      stant                                                                             δ (%)                                                                       -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                              V/mm                                                                               25° C.                                                                        150° C.                                                                        AC DC                                                                               of reject                                                                          (h)                __________________________________________________________________________     *2301                                                                              1300                                                                               1560                                                                              0.8                                                                               4   -13 5   -18 18  -39 5200                                                                              4940                                                                              230                                                                               220 12 14                                                                               0/72                                                                               880                  *2302 1300  810 0.7 2.4 -7 4 -7 7 -10 5430 5160 200 190 12 14 12/72                                                                      920                  *2303 1300 1330 0.8 2.2 -7.8 5 -8 8 -22 3000 2100  90  60 12 14 0/72                                                                     860                  *2304 1300 1330 0.7 2.4 -14.2 4.8 -27 27 -22 5230 4970 220 210 12 14                                                                     0/72 130           *2305                                                                              Unmeasurable due to semiconductor formation                                *2306                                                                              1280                                                                               1120                                                                              0.8                                                                               3.4 -8.3                                                                               4.6 -19 19  -13 3080                                                                              2930                                                                              130                                                                               120 12 14                                                                               0/72                                                                               120                *2307                                                                              Unmeasurable due to semiconductor formation                                *2308                                                                              1300                                                                               1440                                                                              0.7                                                                               3.2 -8.2                                                                               4.1 -9  9   -37 3200                                                                              3040                                                                              120                                                                               110 10 12                                                                               0/72                                                                               110                *2309                                                                              Unmeasurable due to insufficient sintering                                   *2310 Unmeasurable due to insufficient sintering                               *2311 Unmeasurable due to insufficient sintering                             *2312                                                                              1300                                                                               1280                                                                              2.2                                                                               3.3 -8.7                                                                               4.3 -9.2                                                                               9.2 -22 3310                                                                              3150                                                                              130                                                                               120 11 11                                                                               0/72                                                                               140                *2313                                                                              Unmeasurable due to insuffieient sintering                                 *2314                                                                              1300                                                                               1420                                                                              2.4                                                                               2.7 -7.6                                                                               3.6 -8  8   -36 3200                                                                              3040                                                                              150                                                                               140 10 11                                                                               0/72                                                                               170                  *2315 1300 1120 0.7 2.4 -7.2 5 -9.1 9.1 -14 5240 4980 210 200 12 14                                                                      0/72 900                                                                        2316 1280                                                                     1220 0.7 2.4                                                                   -8.4 4.5 -11                                                                   11 -21 5130                                                                    4870 250 240                                                                   12 14 0/72                                                                     850                  2317 1280 1450 0.7 2.6 -8.6 4.6 -12.1 12.1 -37 5160 4900 230 220 13 15                                                                   0/72 890           __________________________________________________________________________

                                      TABLE 41                                     __________________________________________________________________________                                          Product CR (Ω · F)                                              315                                                                               945        Insula-                                                                             Humid-                        DC vias V V   tion ity                                                       Di-  charac- Im- Im-   break- Resis-                                          Di- elec- Ratio of Temperature Dependent teristic press- press- 315 V                                                                  945 V down                                                                     tance                                                                             elec- tric                                                                  apacitance                                                                     Change (%)                                                                     (%) ed ed Im-                                                                  Im- voltage                                                                    Load Mean          Sam-                                                                              Baking                                                                             tric                                                                              Loss               Maxi-                                                                              ΔC/C                                                                         Volt-                                                                             Volt-                                                                             pressed                                                                            pressed                                                                            (kV/ Test                                                                               Life                 ple Temp. Con- tan ΔC/C.sub.20 ΔC/C.sub.25 mum 5 k age age                                                                   Voltage                                                                        Voltage mm)                                                                    Number Span        No.                                                                               (° C.)                                                                      stant                                                                             δ (%)                                                                       -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                              V/mm                                                                               25° C.                                                                        150° C.                                                                         AC DC                                                                               of reject                                                                          (h)                __________________________________________________________________________     2318                                                                              1280                                                                               1360                                                                              0.8                                                                               3   -9  4.7 -10.4                                                                              10.4                                                                               -28 5200                                                                              4940                                                                              220 210 12 14                                                                               0/72                                                                               930                  2319 1300 1370 0.7 3.4 -9.1 4.5 -9.7 9.7 -30 5080 4830 240 230 12 14                                                                     0/72 870                                                                        2320 1300                                                                     1240 0.7 2.8                                                                   -8.7 5 -9.5                                                                    9.5 -22 5140                                                                   4880 230 220                                                                   12 14 0/72                                                                     830                  2321 1300 1510 0.7 2.6 -8.5 4.8 -13.4 13.4 -39 5300 5040 230 220 12 14                                                                   0/72 950                                                                        2322 1300                                                                     1360 0.7 2 -9                                                                  4.6 -10.3                                                                      10.3 -29 5220                                                                  4960 210 200                                                                   12 14 0/72                                                                     880                  2323 1300 1460 0.7 3 -9.2 4.9 -11.2 11.2 -38 5290 5030 250 240 12 14                                                                     0/72 900                                                                        2324 1280                                                                     1250 0.8 3.2                                                                   -8.8 4.6 -11                                                                   11 -23 5340                                                                    5070 230 220                                                                   13 15 0/72                                                                     860                  2325 1300 1240 0.7 3.3 -8.7 4.3 -12 12 -23 5330 5060 220 210 12 14 0/72                                                                  830                  2326 1300  960 0.7 2.9 -9.2 5.1 -12.5 12.5 -12 5080 4830 200 190 13 15                                                                   0/72 810                                                                        2327 1300                                                                     1340 0.7 2.8                                                                   -9.3 5.3                                                                       -12.1 12.1                                                                     -30 5210 4950                                                                  210 200 12 14                                                                  0/72 870                                                                        2328 1280                                                                     1440 0.7 2.1                                                                   -8.5 4 -11.5                                                                   11.5 -38 5240                                                                  4980 220 2i0                                                                   12 14 0/72                                                                     9i0                  2329 1300 1470 0.8 2.6 -8.2 4.6 -13.6 13.6 -39 5260 S000 230 220 12 14                                                                   0/72 950                                                                        2330 1300                                                                     1360 0.7 3                                                                     -8.8 4.2                                                                       -11.8 11.8                                                                     -28 5220 4960                                                                  220 2i0 i2 14                                                                  0/72 880                                                                        2331 1280                                                                     1420 0.8 2.7                                                                   -9 4.8 -11.9                                                                   11.9 -36 5240                                                                  4980 210 200                                                                   12 14 0/72                                                                     930                  2332 1300 1430 0.7 2.8 -8.6 4.7 -11 11 -36 5280 S020 230 220 12 14 0/72                                                                  910                  2333 1300 1460 0.7 3 -9.i 4.3 -10.7 10.7 -39 S300 S040 220 210 i2 14                                                                     0/72 860           __________________________________________________________________________

It is evident from Table 38 to TABLE 41 that the monolithic ceramic capacitor according to the present invention has a capacitance decreasing ratio of as small as within -40% or less at an impressed voltage of 5 kV/mm and a dielectric loss of less than 1.0 %, wherein the rate of change against temperature changes satisfies both the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing, temperature of 1300° C. or less.

The reason why the composition was limited in the present invention will be described hereinafter.

In the composition of (BaO)_(m) TiO₂ +βR₂ O₃ +γBaZrO₃ +gMnO (wherein R₂ O₃ represents at least one compound selected from Eu₂ O₃, Gd₂ O₃, Tb₂ O₃, Dy₂ O₃, Ho₂ O₃, Er₂ O₃, Tm₂ O₃ and Yb₂ O₃, β, γ and g representing mole ratio, respectively), a R₂ O₃ content β of less than about 0.001 as shown in the sample No. 2301 is not preferable because the temperature characteristics does not satisfy the B-level/X7R characteristics. On the other hand, a Ra₂ O₃ content β of more than about 0.06 as shown in the sample No. 2302 is also not preferable because the specific dielectric constant becomes as small as less than 900. Accordingly, the preferable range of the Ra₂ O₃ content β is 0.001≦β≦0.06.

A BaZrO₃ content γ of zero as in the sample No. 2303 is not preferable since the insulation resistance is low and the voltage dependency of the insulating resistance is larger than that of the composition system containing BaZrO₃. It is also not preferable that the BaZrO₃ content γ is more than about 0.06 as in the sample No. 2304 because the temperature characteristic does not satisfy the B-level/X7R characteristics, along with shortening the mean life span. Accordingly, the preferable range of the BaZrO₃ content γ is 0.005≦γ≦0.06.

It is not preferable that, as seen in the sample No. 2305, the MnO content g is about 0.001 since measuring is impossible due to formation of semiconductors. On the other hand, it is not preferable that the MnO content g exceeds about 0.13 as in the sample No. 2306, because the temperature characteristic X7R is not satisfied and the insulation capacitance is low along with the mean life span being short. Accordingly, the MnO content g is preferably in the range of 0.001≦g<0.13.

It is not preferable that the BaO/TiO₂ ratio m is less than about 1.000 as in the sample No. 2307 because measurements are impossible due to formation of semiconductors. It is also not preferable that, as seen in the sample No. 2308, the BaO/TiO₂ ratio m is about 1.000 since the insulation resistance as well as the AC and DC breakdown voltage becomes low along with shortening the mean life span. It is not preferable, on the other hand, that the BaO/TiO₂ ratio m is over about 1.035 as in the samples No. 2309 and 2310 since measurements becomes impossible due to insufficient sintering. Accordingly, the BaO/TiO₂ ratio m in the range of 1.000<m≦1.035 is preferable.

It is not preferable that the amount of addition of the first or second side component is zero as in the samples No. 2311 and 2313 because measurements are impossible due to insufficient sintering. It is not preferable that the amount of addition of the first or second side component exceeds about 3.0 parts by weight as seen in the samples No. 2312 and 314, on the other hand, because the dielectric loss exceeds 1.0% and the insulation resistance and insulation breakdown voltage are lowered alone with shortening the mean life span. Accordingly, the preferable content of either the first or the second components is about 0.2 to 3.0 parts by weight.

The content of the alkali earth metal oxides contained in barium titanate as impurities is below about 0.02% by weight because when the contents of the alkali earth metal oxides exceeds about 0.02% by weight as in the sample No. 2315, the dielectric constant is decreased.

Example 17

A material with a composition of BaO₁.010 TiO₂ +0.015Ho₂ O₃ +0.01BaZrO₃ +0.03 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method as in Example 1, except that an oxide represented by Li₂ O--(Si, Ti)O₂ --MO shown in Table 34, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the first side component. The overall dimensions of the monolithic ceramic capacitor produced is the same as in Example 13. The electric characteristics were measured by the same method as in Example 13. The results are shown in TABLE 42. In Table 42, the samples No. 2401 to 2422 correspond to the samples No. 2101 to 2122 in TABLE 34. For example, the sample No. 2401 in TABLE 42 was obtained by adding the side component of the sample No. 2101 in TABLE 34.

                                      TABLE 42                                     __________________________________________________________________________                                          Product CR (Ω · F)                                              315                                                                               945        Insula-                                                                             Humid-                        DC vias V V   tion ity                                                       Di-  charac- Im- Im-   break- Resis-                                          Di- elec- Ratio of Temperature Dependent teristic press- press- 315 V                                                                  945 V down                                                                     tance                                                                             elec- tric                                                                  apacitance                                                                     Change (%)                                                                     (%) ed ed Im-                                                                  Im- voltage                                                                    Load Mean          Sam-                                                                              Baking                                                                             tric                                                                              Loss               Maxi-                                                                              ΔC/C                                                                         Volt-                                                                             Volt-                                                                             pressed                                                                            pressed                                                                            (kV/ Test                                                                               Life                 ple Temp. Con- tan ΔC/C.sub.20 ΔC/C.sub.25 mum 5 k age age                                                                   Voltage                                                                        Voltage mm)                                                                    Number Span        No.                                                                               (° C.)                                                                      stant                                                                             δ (%)                                                                       -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                              V/mm                                                                               25° C.                                                                        150° C.                                                                         AC DC                                                                               of reject                                                                          (h)                __________________________________________________________________________     2401                                                                              1300                                                                               1430                                                                              0.7                                                                               2.6 -8.4                                                                               3.6 -10.1                                                                              10.1                                                                               -36 5200                                                                              4850                                                                              220 210 12 14                                                                               0/72                                                                               880                  2402 1300 1430 0.6 2.3 -8.4 3.4 -10.5 10.5 -36 5120 4860 210 200 12 14                                                                   0/72 900                                                                        2403 1280                                                                     1440 0.7 2.5                                                                   -8 4.1 -10.6                                                                   10.6 -36 5230                                                                  4970 200 190                                                                   12 14 0/72                                                                     870                  2404 1300 1470 0.7 2.2 -8.1 4.2 -11 11 -38 5100 4850 230 220 12 14 0/72                                                                  820                  2405 1300 1430 0.7 2.2 -7.9 4 -11.3 11.3 -36 5160 4900 230 220 13 15                                                                     0/72 820                                                                        2406 1280                                                                     1430 0.7 2.7                                                                   -8 4.2 -11.5                                                                   11.5 -36 5230                                                                  4970 210 200                                                                   12 14 0/72                                                                     950                  2407 1300 1430 0.7 2.6 -8.2 3.9 -10.5 10.5 -36 5140 4880 220 210 13 15                                                                   0/72 830                                                                        2408 1280                                                                     1460 0.6 2.8                                                                   -8.3 4.1 -11                                                                   11 -37 5510                                                                    4890 220 210                                                                   12 14 0/72                                                                     800                  2409 1280 1460 0.7 2.4 -8 4.2 -12.1 12.1 -37 5120 4860 200 190 12 14                                                                     0/72 880                                                                        2410 1280                                                                     1480 0.7 2.3                                                                   -8.1 4.1                                                                       -11.7 11.7                                                                     -38 5130 4870                                                                  220 210 12 14                                                                  0/72 850                                                                        2411 1300                                                                     1440 0.7 2.4                                                                   -8.2 3.9                                                                       -11.6 11.6                                                                     -36 5140 4880                                                                  220 210 12 14                                                                  0/72 810                                                                        2412 1280                                                                     1420 0.6 2.2                                                                   -8.3 3.8                                                                       -11.5 11.5                                                                     -36 5260 5000                                                                  200 190 12 14                                                                  0/72 920           2413                                                                              1350                                                                               Unmeasurable due to insufficient sintering                                2414 1350 Unmeasurable due to insufficient sintering                         2415                                                                              1350                                                                               1440                                                                              1.8                                                                               2.8 -8  3.8 -11 11  -38 5220                                                                              4960                                                                              190 180 11 12                                                                               55/72                                                                              120                2416                                                                              1350                                                                               Unmeasurable due to insufficient sintering                                2417 1350 Unmeasurable due to insufficient sintering                         2418                                                                              1300                                                                               1460                                                                              0.8                                                                               2.7 -8.2                                                                               4.1 -10.7                                                                              10.7                                                                               -37 5170                                                                              4910                                                                              210 200 11 13                                                                               0/72                                                                               860                  2419 1350 1430 1.6 2.5 -8.3 4.2 -10.8 10.8 -36 5280 5020 220 210 11 13                                                                   33/72 110                                                                       2420 1300                                                                     1440 0.7 2.5                                                                   -8.4 4 -11.5                                                                   11.5 -37 5100                                                                  4850 190 180                                                                   12 13 6/72                                                                     870                  2421 1350 1460 1.8 2.7 -8.3 3.9 -10 10 -37 5160 4900 190 180 11 13                                                                       52/72 130                                                                       2422 1350                                                                     1420 1.6 2.5                                                                   -8.2 3.7                                                                       -10.7 10.7                                                                     -36 5200 4940                                                                  200 190 11 13                                                                  49/72              __________________________________________________________________________                                                                 140           

As is evident from the samples No. 2401 to 2412, 2418 and 2420, preferable results are obtained in the samples in which oxides of the samples No. 2101 to 2112, 2118 and 2120 in TABLE 34 with compositions within or on the boundary lines of the area surrounded by the straight lines connecting by A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D(x=35, y=45, z=20), E (x=45, y=45, z=10) and F(x=45, y=55, z=0) (wherein x, y and z represent mole %, w represents mole ratio, w being within the range of 0.3≦w<1.0 when it falls on the line A-F) in the three component phase diagram of the oxides represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO in FIG. 4 are added, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 190 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

When the oxide represented by Li₂ O--(Si_(w), Ti_(1-w))O₂ --MO has a composition outside of the composition described above as in the samples No. 2113 to 2117 and 2119, on the other hand, sintering becomes insufficient or many rejection appear in the humidity resistance load test even after sintering as seen in the samples No. 2413 to 2417 and 2419 in TABLE 42. When the composition falls on the line A-F and w=1.0 as in the samples No. 2119 and 2121 in TABLE 34, the sintering temperature becomes high and many rejects appear in the humidity resistance load test. When the value of w is less than 0.30 as in the sample No. 2122 in TABLE 34, he sintering temperature becomes high and many rejects appear in the humidity resistance load test as seen in the sample No. 2422 in TABLE 42.

Example 18

A material with a composition of BaO₁.010 TiO₂ +0.025Eu₂ O₃ +0.01BaZrO₃ +0.05 MnO (mole ratio) was prepared using barium titanate A of TABLE 1 as a dielectric powder. A monolithic ceramic capacitor was produced by the same method and same overall dimensions as in Example 13, except that an oxide SiO₂ --TiO₂ --XO shown in Table 38, having a mean particle size of 1 μm or less produced by heating the material described above at 1200 to 1500° C., was added as the second side component. The electric characteristics were measured by the same method as in Example 13. The results are shown in TABLE 43. The samples No. 2501 to 2519 in TABLE 43 correspond to the samples No. 2201 to 2219 in TABLE 36. For example, sample No.2501 in TABLE 43 was obtained by adding the side component of the sample No. 2201 in TABLE 36.

                                      TABLE 43                                     __________________________________________________________________________                                          Product CR (Ω · F)                                              315                                                                               945        Insula-                                                                             Humid-                        DC vias V V   tion ity                                                       Di-  charac- Im- Im-   break- Resis-                                          Di- elec- Ratio of Temperature Dependent teristic press- press- 315 V                                                                  945 V down                                                                     tance                                                                             elec- tric                                                                  apacitance                                                                     Change (%)                                                                     (%) ed ed Im-                                                                  Im- voltage                                                                    Load Mean          Sam-                                                                              Baking                                                                             tric                                                                              Loss               Maxi-                                                                              ΔC/C                                                                         Volt-                                                                             Volt-                                                                             pressed                                                                            pressed                                                                            (kV/ Test                                                                               Life                 ple Temp. Con- tan ΔC/C.sub.20 ΔC/C.sub.25 mum 5 k age age                                                                   Voltage                                                                        Voltage mm)                                                                    Number Span        No.                                                                               (° C.)                                                                      stant                                                                             δ (%)                                                                       -25° C.                                                                     85° C.                                                                      -55° C.                                                                     125° C.                                                                     value                                                                              V/mm                                                                               25° C.                                                                        150° C.                                                                         AC DC                                                                               of reject                                                                          (h)                __________________________________________________________________________     2501                                                                              1300                                                                               1350                                                                              0.9                                                                               2.2 -8.3                                                                               3.6 -10.2                                                                              10.2                                                                               -32 5120                                                                              4860                                                                              230 220 12 14                                                                               0/72                                                                               870                  2502 1300 1350 0.8 2.3 -8.6 4.1 -10.4 10.4 -32 5210 4950 240 230 12 14                                                                   0/72 920                                                                        2503 1300                                                                     1360 0.9 2.4                                                                   -8.7 4 -11 11                                                                  -32 5130 4870                                                                  220 210 12 14                                                                  0/72 860                                                                        2504 1300                                                                     1320 0.8 2.3                                                                   -9 3.8 -11.6                                                                   11.6 -31 5140                                                                  4880 230 220                                                                   13 15 0/72                                                                     840                  2505 1300 1360 0.9 2.2 -8.2 3.9 -10.8 10.8 -32 5160 4900 220 210 12 14                                                                   0/72 920                                                                        2506 1300                                                                     1340 0.8 2.3                                                                   -8.6 4 -10.7                                                                   10.7 -32 5120                                                                  4860 210 200                                                                   12 14 0/72                                                                     910                  2507 1300 1310 0.9 2.6 -8.4 4.2 -11 11 -30 5240 4980 230 220 13 15 0/72                                                                  880                  2508 1300 1340 0.9 2.5 -8.2 4 -11.5 11.5 -32 5230 4970 220 210 12 14                                                                     0/72 900                                                                        2509 1300                                                                     1330 0.9 2.3                                                                   -8.3 3.7                                                                       -11.6 11.6                                                                     -31 5200 4940                                                                  220 210 12 14                                                                  0/72 920                                                                        2510 1300                                                                     1370 0.9 2.1                                                                   -8.4 3.5                                                                       -11.3 11.3                                                                     -33 5030 4780                                                                  210 200 12 14                                                                  0/72 930                                                                        2511 1300                                                                     1360 0.8 2.2                                                                   -8.6 3.8                                                                       -10.9 10.9                                                                     -32 5430 5160                                                                  340 320 12 14                                                                  0/72 850                                                                        2512 1300                                                                     1350 0.9 2.6                                                                   -8.3 3.6                                                                       -10.7 10.7                                                                     -32 5410 5140                                                                  330 310 12 14                                                                  0/72 900                                                                        2513 1350                                                                     1330 0.9 2.4                                                                   -8.4 4 -11 11                                                                  -31 5120 4860                                                                  220 210 11 13                                                                  55/72  120         2514                                                                              1350                                                                               Unmeasurable due to sintering                                             2515 1350 Unmeasurable due to sintering                                      2516                                                                              1350                                                                               1320                                                                              1  2.3 -8.5                                                                               3.8 -11.5                                                                              11.5                                                                               -30 5160                                                                              4900                                                                              230 220 11 13                                                                               64/72                                                                              110                2517                                                                              1350                                                                               Unmeasurable due to sintering                                             2519 1350 Unmeasurable due to sintering                                        2519 1350 Unmeasurable due to sintering                                      __________________________________________________________________________

As is evident from the samples No. 2501 to 2512 in TABLE 43, preferable results are obtained in the samples in which oxides of the samples No. 2201 to 2212 in TABLE 36 with compositions within or on the boundary lines of the area surrounded by the straight lines connecting A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60) (wherein x, y and z represent mole %) in the three component phase diagram of the SiO₂ --TiO₂ --XO oxides shown in FIG. 5 are added, wherein the samples have a capacitance decreasing ratio of as small as within -40% at an impressed voltage of 5 kV/mm and a dielectric loss of 1.0% or less, along with the rate of change of the electrostatic capacitance against temperature changes satisfying the B-level characteristic standard stipulated in the JIS Standard in the temperature range of -25° C. to +85° C. and X7R-level characteristic standard stipulated in the EIA standard in the temperature range of -55° C. to +125° C.

Moreover, the insulation resistances at 25° C. and 150° C. as expressed by the product CR show as high values as 5000 Ω•F or more and 200 Ω•F or more, respectively, when the ceramic capacitor is used under a high electric field strength of 10 kV/mm. The insulation breakdown voltage also shows high values of 12 kV/mm or more under the AC voltage and 14 kV/mm or more under the DC voltage. In addition, an acceleration test at 150° C. and DC 25 kV/mm gave a mean life span as long as 800 hours or more besides enabling a relatively low firing temperature of 1300° C. or less.

When the oxide SiO₂ --TiO₂ --XO has a composition outside of the composition described above as in the samples No. 2213 to 2119 in TABLE 36, on the other hand, sintering becomes insufficient or many rejection appear in the humidity resistance load test even after sintering as seen in the samples No. 2513 to 2519 in TABLE 43.

While a monolithic capacitor having an insulation resistance of 5400 Ω•F or more and 330 Ω•F or more at 25° C. and 150° C., respectively, under a strong electric field of 10 kV/mm can be obtained by allowing Al₂ O₃ and/or ZrO₂ in the SiO₂ --TiO₂ --XO oxides as in the sample No. 2211 and 2212 in TABLE 36, the sintering property is extremely decreased as shown in the samples NO. 2517 and 2518 in TABLE 43 when Al₂ O₃ and ZrO₂ are added in an amounts of about 15 parts by weight or more and about 5 parts by weight or more, respectively, as in the samples No. 2517 and 2518 in TABLE 43.

Although powders prepared by the oxalic acid method are used in the foregoing examples, the methods are not limited thereto but a powder of barium titanate prepared by an alkoxide method or hydrothermal synthesis method may be used. It may happen that the characteristics of the monolithic ceramic capacitor are more improved than those shown in the foregoing examples by using these powders.

The oxide powders as starting materials are not limited to those hitherto described, and the resulting characteristics are not affected in any sense by using a solution of an alkoxide or organometals compound provided that the starting materials are formulated so as to construct the dielectric ceramic layers within the scope of the present invention.

It is made clear from the foregoing descriptions that the dielectric ceramic composition according to the present invention is not reduced by firing in the reducing atmosphere and is not formed into semiconductors, and sintering is possible at a relatively low temperature of about 1300° C. or less.

Accordingly, when a monolithic ceramic capacitor is constricted by using this dielectric ceramic composition as dielectric ceramic layers, the production cost of the monolithic ceramic capacitor can be reduced since base metals such as nickel or nickel alloys may be used for the electrode materials.

When the monolithic ceramic capacitor using this dielectric ceramic composition is used under a high electric field of 10 kV/mm where reliability can not be ensured due to low insulation resistance in the monolithic ceramic capacitor using nickel or nickel alloys for the conventional inner electrodes, a monolithic ceramic capacitor excellent in weather resistance properties such as high temperature load at an impressed voltage of DC 25 kV/mm at 150° C. and humidity resistance load can be obtained, wherein the insulation resistances at room temperature and at 150° C. represented by the product of the insulation resistance and electrostatic capacitance (CR) becomes as high as 4900 to 5000 Ω•F and 190 to 200 Ω•F, respectively, the voltage dependency of the insulation resistance is low, the capacitance decrease ratio at an impressed voltage of 5 kV/mm is as small as 40 to 45% and the insulation durability is high, and the temperature characteristics of the electrostatic capacitance satisfies the B-level characteristic standard stipulated in the JIS Standard and X7R-level characteristic standard stipulated in the EIA standard. 

What is claimed:
 1. A dielectric ceramic composition comprising barium titanate containing about 0.02% by weight or less of alkali metal oxides; at least one of scandium oxide or yttrium oxide; at least one of europium oxide, gadolinilinm oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thuliumi oxide and ytterbium oxide; barium zirconate and manganese oxide, as an essential component represented by the composition formula

    (BaO).sub.m TiO.sub.2 +αM.sub.2 O.sub.3 +βR.sub.2 O.sub.3 +β'R'.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

wherein M is at least one of Sc and Y; R is at least one of Eu, Gd, Tb and Dy; R' is at least one of R, Ho, Er, Tm and Yb; α≦0.06; β≦0.06; β'≦0.06; 0.005≦γ0.06; 0.001<g≦0.13; α+β+β'<0.06; and 1.000<m<1.035; provided at least one of β and β is 0 and at least one of α, β and β is not 0; and about 0.2 to 3.0 parts by weight of a side component relative to 100 parts by weight of said essential component, wherein said side component is an oxide represented by Li₂ O--(Si, Ti)O₂ --MO or SiO₂ --TiO₂ --XO, wherein MO is at least one of Al₂ O₃ or ZrO₂ and wherein XO is at least one of BaO, CaO, SrO, MgO, ZnO and MnO.
 2. A dielectric ceramic composition according to claim 1, wherein said essential component further contains h moles of magnesium oxide, where 0.001<g≦0.12, 0.001<h≦0.12 and g+h≦0.13.
 3. A dielectric ceramic composition according to claim 1, wherein said essential component is represented by the composition formula

    (BaO).sub.m TiO.sub.2 +αM.sub.2 O.sub.3 +βR.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

and 0.001≦α≦0.05, 0.001≦β0.05, 0.005≦γ≦0.06, 0.001<g≦0.13 and α+β≦0.06, and 1.000<m≦1.035.
 4. A dielectric ceramic composition according to claim 3, wherein said essential component further contains h moles of magnesiumn oxide, where 0.001<g≦0.12, 0.001<h≦0.12 and g+h≦0.13.
 5. A dielectric ceramic composition according to claim 3, wherein said essential component is represented by the composition formula;

    (BaO).sub.m TiO.sub.2 +αM.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

and 0.001≦α≦0.06, 0.005≦γ≦0.06, and 0.001<g≦0.13, and 1.000<m<1.035.
 6. A dielectric ceramic composition according to claim 5, wherein said essential component further contains h mole ratio of magnesium oxide, where 0.001<g≦0.12, 0.001≦h≦0.12 and g+h≦0.13.
 7. A dielectric ceramic composition according to claim 1, wherein said essential component is

    (BaO).sub.m TiO.sub.2 +β'R'.sub.2 O.sub.3 +γBaZrO.sub.3 +gMnO

and 0.001≦β'0.06, 0.005<γ<0.06 and 0.001<g≦0.13, and 1.000<m≦1.025.
 8. A dielectric ceramic composition according to claim 7, wherein said essential component further contains h moles of magnesium oxide, where 0.001≦γ≦0.06, 0.001<g≦0.12, 0.001<h≦0.12 and g+h≦0.13.
 9. A dielectric ceramic composition according to claim 7, wherein said side component has a composition represented by xLi₂ O--y(Si_(w) Ti_(1-w)) O₂ --zMO and wherein x, y and z represent mol % and w is in the range of 0.3≦w≦1.00 and falls within or on the boundary lines of the area surrounded by the 5 straight lines connecting points A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0), provided that when the composition falls on the straight line of A-F, w is within the area of 0.3≦w≦1.0, on a three component phase diagram defined by the apexes corresponding to each component.
 10. A dielectric ceramic composition according to claim 7, wherein said side component has a composition represented by xSiO2--yTiO₂ --zXO and wherein x, y and z represent mol % falling within or on the boundary lines of the area surrounded by straight lines connecting points A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60) on a three component phase diagram defines by the apexes corresponding to each component.
 11. A dielectric ceramic composition according to claim 10, wherein the side component contains in total of about 15 parts by weight or less of at least one of Al₂ O₃ and ZrO₂ in which the content of ZrO₂ is about 5 parts by weight or less, relative to 100 parts by weight of the oxide SiO₂ --TiO₂ --XO.
 12. A dielectric ceramic composition according to claim 5, wherein said side component has a composition represented by xLi₂ O--y(Si_(w) Ti_(1-w))O₂ --zMO and wherein x, y and z represent mol % and w is in the range of 0.3≦w≦1.00 and falls within or on the boundary lines of the area surrounded by the straight lines connecting points A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0), provided that when the composition falls on the straight line of A-F, w is within the area of 0.3≦w≦1.0, on a three component phase diagram defined by the apexes corresponding to each component.
 13. A dielectric ceramic composition according to claim 5, wherein said side component has a composition represented by xSiO2--yTiO₂ --zXO and wherein x, y and z represent mol % falling within or on the boundary lines of the area surrounded by straight lines connecting points A (x=85, y=1, z=14), B (x 35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60) on a three component phase diagram defines by the apexes corresponding to each component.
 14. A dielectric ceramic composition according to claim 3, wherein said side component has a composition represented by xLi₂ O--y(Si_(w), Ti_(1-w))O₂ --zMO and wherein x, y and z represent mol % and w is in the range of 0.3≦w≦1.00 and falls within or on the boundary lines of the area surrounded by the straight lines connecting points A (x=20, y=80, z=0), B (x=10, y=80, z=10), C (x=10, y=70, z=20), D (x=35, y=45, z=20), E (x=45, y=45, z=10) and F (x=45, y=55, z=0), provided that when the composition falls on the straight line of A-F, w is within the area of 0.3≦w≦1.0, on a three component phase diagram defined by the apexes corresponding to each component.
 15. A dielectric ceramic composition according to claim 3, wherein said side component has a composition represented by xSiO2--yTiO₂ --zXO and wherein x, y and z represent mol % falling within or on the boundary lines of the area surrounded by straight lines connecting points A (x=85, y=1, z=14), B (x=35, y=51, z=14), C (x=30, y=20, z=50) and D (x=39, y=1, z=60) on a three component phase diagram defines by the apexes corresponding to each component.
 16. A monolithic ceramic capacitor comprising a plurality of dielectric ceramic layers, a plurality of inner electrodes each of which is between adjacent ceramic layers and outer electrodes electrically connected to said inner electrodes, wherein said dielectric ceramic layers comprise the dielectric ceramic composition according to claim
 1. 17. A monolithic ceramic capacitor comprising a plurality of dielectric ceramic layers, a plurality of inner electrodes each of which is between adjacent ceramic layers and outer electrodes electrically connected to said inner electrodes, wherein said dielectric ceramic layers comprise the dielectric ceramic composition according to claim 3 and said inner electrodes are nickel or a nickel alloy.
 18. A monolithic ceramic capacitor comprising a plurality of dielectric ceramic layers, a plurality of inner electrodes each of which is between adjacent ceramic layers and outer electrodes electrically connected to said inner electrodes, wherein said dielectric ceramic layers comprise the dielectric ceramic composition according to claim 5 and said inner electrodes are nickel or a nickel alloy.
 19. A monolithic ceramic capacitor comprising a plurality of dielectric ceramic layers, a plurality of inner electrodes each of which is between adjacent ceramic layers and outer electrodes electrically connected to said inner electrodes, wherein said dielectric ceramic layers comprise the dielectric ceramic composition according to claim 7 and said inner electrodes are nickel or a nickel alloy.
 20. A monolithic ceramic capacitor according to claim 16, wherein the outer electrode comprises a first sintered layer of an electroconductive metal powder or an electroconductive metal powder and glass frit and an optional second layer comprising a plating layer on said first layer. 